Facebook, Inc. is an American online social media and social networking service company based in Menlo Park, California. It was founded by Mark Zuckerberg, along with fellow Harvard College students and roommates Eduardo Saverin, Andrew McCollum, Dustin Moskovitz and Chris Hughes. It is considered one of the Big Four technology companies along with Amazon, Apple, and Google.
The founders initially limited the website's membership to Harvard students and subsequently Columbia, Stanford, and Yale students. Membership was eventually expanded to the remaining Ivy League schools, MIT, and higher education institutions in the Boston area, then various other universities, and lastly high school students. Since 2006, anyone who claims to be at least 13 years old has been allowed to become a registered user of Facebook, though this may vary depending on local laws. The name comes from the face book directories often given to American university students. Facebook held its initial public offering (IPO) in February 2012, valuing the company at $104 billion, the largest valuation to date for a newly listed public company. Facebook makes most of its revenue from advertisements that appear onscreen and in users' News Feeds.
The Facebook service can be accessed from devices with Internet connectivity, such as personal computers, tablets and smartphones. After registering, users can create a customized profile revealing information about themselves. They can post text, photos and multimedia which is shared with any other users that have agreed to be their "friend". Users can also use various embedded apps, join common-interest groups, and receive notifications of their friends' activities. Facebook claimed that had more than 2.3 billion monthly active users as of December 2018. However, it faces a big problem of fake accounts. It caught 3 billion fake accounts in the last quarter of 2018 and the first quarter of 2019. Many critics questioned whether Facebook knows how many actual users it has. Facebook is one of the world's most valuable companies.
It receives prominent media coverage, including many controversies. These often involve user privacy (as with the Cambridge Analytica data scandal), political manipulation (as with the 2016 U.S. elections), psychological effects such as addiction and low self-esteem, and content that some users find objectionable, including fake news, conspiracy theories, and copyright infringement. Facebook also does not remove false information from its pages, which brings continuous controversies. Commentators have stated that Facebook helps to spread false information and fake news.
Facebook offers other products and services. It acquired Instagram, WhatsApp, Oculus, and GrokStyle and independently developed Facebook Messenger, Facebook Watch, and Facebook Portal.
1.1 2003–2006: Thefacebook, Thiel investment, and name change
1.2 2006–2012: Public access, Microsoft alliance, and rapid growth
1.3 2012–2013: IPO, lawsuits, and one-billionth user
1.4 2013–2014: Site developments, A4AI, and 10th anniversary
1.5 2015–present: Fake news, vaccine hesitancy, and Christchurch shooting
2 Corporate affairs
2.2 Board of directors
2.4 Mergers and acquisitions
2.6 Data centers
2.7 Tax affairs
3.1 Technical aspects
3.3 User profile/personal timeline
3.4 News Feed
3.5 Like button
3.6 Instant messaging
3.8 Privacy controls
3.9 Facebook Bug Bounty Program
4.1 User growth
5 Criticisms and controversies
5.3 Political manipulation
5.4 Company governance
5.5 Definers Public Affairs
5.6 Spreading political messages by obtaining transcripts of user audio
6.4 Emotional health
7 See also
9 Further reading
10 External links
Further information: History of Facebook
2003–2006: Thefacebook, Thiel investment, and name change
Zuckerberg built a website called "Facemash" in 2003 while attending Harvard University. The site was comparable to Hot or Not and used "photos compiled from the online facebooks of nine Houses, placing two next to each other at a time and asking users to choose the "hotter" person". Facemash attracted 450 visitors and 22,000 photo-views in its first four hours. The site was sent to several campus group list-servers, but was shut down a few days later by Harvard administration. Zuckerberg faced expulsion and was charged with breaching security, violating copyrights and violating individual privacy. Ultimately, the charges were dropped. Zuckerberg expanded on this project that semester by creating a social study tool ahead of an art history final exam. He uploaded all art images to a website, each of which was accompanied by a comments section, then shared the site with his classmates.
Original layout and name of Thefacebook in 2004, showing actor Al Pacino's face superimposed with binary numbers as Facebook's original logo, designed by co-founder Andrew McCollum
A "face book" is a student directory featuring photos and personal information. In 2003, Harvard had only a paper version along with private online directories. Zuckerberg told the Crimson, "Everyone's been talking a lot about a universal face book within Harvard. ... I think it's kind of silly that it would take the University a couple of years to get around to it. I can do it better than they can, and I can do it in a week." In January 2004, Zuckerberg coded a new website, known as "TheFacebook", inspired by a Crimson editorial about Facemash, stating, "It is clear that the technology needed to create a centralized Website is readily available ... the benefits are many." Zuckerberg met with Harvard student Eduardo Saverin, and each of them agreed to invest $1,000 in the site. On February 4, 2004, Zuckerberg launched "TheFacebook", originally located at thefacebook.com.
Six days after the site launched, Harvard seniors Cameron Winklevoss, Tyler Winklevoss, and Divya Narendra accused Zuckerberg of intentionally misleading them into believing that he would help them build a social network called HarvardConnection.com. They claimed that he was instead using their ideas to build a competing product. The three complained to the Crimson and the newspaper began an investigation. They later sued Zuckerberg, settling in 2008 for 1.2 million shares (worth $300 million at Facebook's IPO).
Membership was initially restricted to students of Harvard College. Within a month, more than half the undergraduates had registered. Dustin Moskovitz, Andrew McCollum, and Chris Hughes joined Zuckerberg to help manage the growth of the website. In March 2004, Facebook expanded to Columbia, Stanford and Yale. and then to all Ivy League colleges, Boston University, New York University, MIT, and successively most universities in the United States and Canada.
In mid-2004, Napster co-founder and entrepreneur Sean Parker—an informal advisor to Zuckerberg—became company president. In June 2004, the company moved to Palo Alto, California. It received its first investment later that month from PayPal co-founder Peter Thiel. In 2005, the company dropped "the" from its name after purchasing the domain name facebook.com for US$200,000. The domain had belonged to AboutFace Corporation.
Mark Zuckerberg, co-creator of Facebook, in his Harvard dorm room, 2005
In May 2005, Accel Partners invested $12.7 million in Facebook, and Jim Breyer added $1 million of his own money. A high-school version of the site launched in September 2005. Eligibility expanded to include employees of several companies, including Apple Inc. and Microsoft.
2006–2012: Public access, Microsoft alliance, and rapid growth
On September 26, 2006, Facebook opened to everyone at least 13 years old with a valid email address. By late 2007, Facebook had 100,000 pages on which companies promoted themselves. Organization pages began rolling out in May 2009. On October 24, 2007, Microsoft announced that it had purchased a 1.6% share of Facebook for $240 million, giving Facebook a total implied value of around $15 billion. Microsoft's purchase included rights to place international advertisements.
In October 2008, Facebook announced that its international headquarters would locate in Dublin, Ireland. In September 2009, Facebook said that it had achieved positive cash flow for the first time. A January 2009 Compete.com study ranked Facebook the most used social networking service by worldwide monthly active users.
The company announced 500 million users in July 2010. Half of the site's membership used Facebook daily, for an average of 34 minutes, while 150 million users accessed the site from mobile devices. A company representative called the milestone a "quiet revolution." In November 2010, based on SecondMarket Inc. (an exchange for privately held companies' shares), Facebook's value was $41 billion. The company had slightly surpassed eBay to become the third largest American web company after Google and Amazon.com.
On November 15, 2010, Facebook announced it had acquired the domain name fb.com from the American Farm Bureau Federation for an undisclosed amount. On January 11, 2011, the Farm Bureau disclosed $8.5 million in "domain sales income", making the acquisition of FB.com one of the ten highest domain sales in history.
In February 2011, Facebook announced plans to move its headquarters to the former Sun Microsystems campus in Menlo Park, California. In March 2011, it was reported that Facebook was removing about 20,000 profiles daily for violations such as spam, graphic content and underage use, as part of its efforts to boost cyber security. Statistics showed that Facebook reached one trillion page views in the month of June 2011, making it the most visited website tracked by DoubleClick. According to a Nielsen study, Facebook had in 2011 become the second-most accessed website in the U.S. behind Google.
China blocked Facebook in 2009.
2012–2013: IPO, lawsuits, and one-billionth user
Main article: Initial public offering of Facebook
In March 2012, Facebook announced App Center, a store selling applications that operate via the website. The store was to be available on iPhones, Android devices, and mobile web users. In April 2012, Facebook acquired Instagram for approximately US$1 billion in cash and stock.
Facebook's initial public offering came on May 17, 2012, at a share price of US$38. The company was valued at $104 billion, the largest valuation to that date. The IPO raised $16 billion, the third-largest in U.S. history, after Visa Inc. in 2008 and AT&T Wireless in 2000. Based on its 2012 income of $5 billion, Facebook joined the Fortune 500 list for the first time in May 2013, ranked 462. The shares set a first day record for trading volume of an IPO (460 million shares). The IPO was controversial given the immediate price declines that followed. and was the subject of lawsuits, while SEC and FINRA both launched investigations.
Billboard on the Thomson Reuters building welcomes Facebook to NASDAQ, 2012
Zuckerberg announced at the start of October 2012 that Facebook had one billion monthly active users, including 600 million mobile users, 219 billion photo uploads and 140 billion friend connections.
2013–2014: Site developments, A4AI, and 10th anniversary
On January 15, 2013, Facebook announced Facebook Graph Search, which provides users with a "precise answer", rather than a link to an answer by leveraging data present on its site. Facebook emphasized that the feature would be "privacy-aware", returning results only from content already shared with the user. On April 3, 2013, Facebook unveiled Facebook Home, a user-interface layer for Android devices offering greater integration with the site. HTC announced HTC First, a phone with Home pre-loaded.
On April 15, 2013, Facebook announced an alliance across 19 states with the National Association of Attorneys General, to provide teenagers and parents with information on tools to manage social networking profiles. On April 19 Facebook modified its logo to remove the faint blue line at the bottom of the "F" icon. The letter F moved closer to the edge of the box.
Following a campaign by 100 advocacy groups, Facebook agreed to update its policy on hate speech. The campaign highlighted content promoting domestic violence and sexual violence against women and led 15 advertisers to withdrawal, including Nissan UK, House of Burlesque and Nationwide UK. The company initially stated, "while it may be vulgar and offensive, distasteful content on its own does not violate our policies". It took action on May 29.
On June 12, Facebook announced that it was introducing clickable hashtags to help users follow trending discussions, or search what others are talking about on a topic. San Mateo County, California, became the top wage-earning county in the country after the fourth quarter of 2012 because of Facebook. The Bureau of Labor Statistics reported that the average salary was 107% higher than the previous year, at $168,000 a year, more than 50% higher than the next-highest county, New York County (better known as Manhattan), at roughly $110,000 a year.
Facebook joined Alliance for Affordable Internet (A4AI) in October, as it launched. The A4AI is a coalition of public and private organizations that includes Google, Intel and Microsoft. Led by Sir Tim Berners-Lee, the A4AI seeks to make Internet access more affordable to ease access in the developing world. On October 13, Facebook acquired Onavo, an Israeli mobile web analytics company. Standard & Poor's added Facebook to its S&P 500 index on December 21.
In February 2014, Facebook announced that it would be buying mobile messaging company WhatsApp for US$19 billion in cash and stock.
In 2014, Facebook bought Oculus VR for $2.3 billion in stock and cash, which released its first consumer virtual reality headset in 2016.
The company celebrated its 10th anniversary during the week of February 3, 2014. In January 2014, over one billion users connected via a mobile device. As of June, mobile accounted for 62% of advertising revenue, an increase of 21% from the previous year. By September Facebook's market capitalization had exceeded $200 billion.
Zuckerberg participated in a Q&A session at Tsinghua University in Beijing, China, on October 23, where he attempted to converse in Mandarin. Zuckerberg hosted visiting Chinese politician Lu Wei, known as the "Internet czar" for his influence in China's online policy, in December 8.
2015–present: Fake news, vaccine hesitancy, and Christchurch shooting
As of January 21, 2015, Facebook's algorithm was revised in an attempt to filter out false or misleading content, such as fake news stories and hoaxes. It relied on users who flag a story accordingly. Facebook maintained that satirical content should not be intercepted. The algorithm was accused of maintaining a "filter bubble", where material the user disagrees with and posts with few likes would be deprioritized. In November, Facebook extended paternity leave from 4 weeks to 4 months.
On April 12, 2016, Zuckerberg outlined his 10-year vision, which rested on three main pillars: artificial intelligence, increased global connectivity and virtual/augmented reality. In June, Facebook announced Deep Text, a natural language processing AI that learns user intent and context in 20 languages. In July, a US$1 billion suit was filed against the company alleging that it permitted Hamas to use it to perform assaults that cost the lives of four people. Facebook released its blueprints of Surround 360 camera on GitHub under an open-source license. In September, it won an Emmy for its animated short "Henry". In October, Facebook announced a fee-based communications tool called Workplace that aims to "connect everyone" at work. Users can create profiles, see updates from co-workers on their news feed, stream live video and participate in secure group chats.
Following the 2016 presidential election, Facebook announced that it would combat fake news by using fact checkers from sites like FactCheck.org and Associated Press (AP), making reporting hoaxes easier through crowdsourcing, and disrupting financial incentives for abusers.
On January 17, 2017, Facebook COO Sheryl Sandberg planned to open Station F, a startup incubator campus in Paris, France. On a six-month cycle, Facebook committed to work with ten to 15 data-driven startups there. On April 18, Facebook announced the beta launch of Facebook Spaces at its annual F8 developer conference. Facebook Spaces is a virtual reality version of Facebook for Oculus VR goggles. In a virtual and shared space, users can access a curated selection of 360-degree photos and videos using their avatar, with the support of the controller. Users can access their own photos and videos, along with media shared on their newsfeed. In September, Facebook announced it would spend up to US$1 billion on original shows for its Facebook Watch platform. On October 16, it acquired the anonymous compliment app tbh, announcing its intention to leave the app independent.
In May 2018 at F8, the company announced it would offer its own dating service. Shares in competitor Match Group fell by 22%. Facebook Dating includes privacy features and friends will be unable to view their friends' dating profile. In July, Facebook was charged £500,000 by UK watchdogs for failing to respond to data erasure requests. On July 18, Facebook established a subsidiary named Lianshu Science & Technology in Hangzhou City, China, with $30 million of capital. All its shares are held by Facebook Hong. Approval of the registration of the subsidiary was then withdrawn, due to a disagreement between officials in Zhejiang province and the Cyberspace Administration of China. On July 26, Facebook became the first company to lose over $100 billion worth of market capitalization in one day, dropping from nearly $630 billion to $510 billion after disappointing sales reports. On July 31, Facebook said that the company had deleted 17 accounts related to the 2018 American elections. On September 19, Facebook announced that, for news distribution outside the United States, it would work with U.S. funded democracy promotion organizations, International Republican Institute and the National Democratic Institute, which are loosely affiliated with the Republican and Democratic parties. Through the Digital Forensic Research Lab Facebook partners with the Atlantic Council, a NATO-affiliated think tank. In November, Facebook launched smart displays branded Portal and Portal Plus (Portal+). They support Amazon's Alexa (intelligent personal assistant service). The devices include video chat function with Facebook Messenger.
In January 2019, the 10 year challenge was started asking users to post a photograph of themselves from 10 years ago (2009) and a more recent photo.
Criticized for its role in vaccine hesitancy, Facebook announced in March 2019 that it would provide users with "authoritative information" on the topic of vaccines.
On March 14, Huffington Post reported that Facebook's PR agency had paid someone to tweak Facebook COO Sheryl Sandberg’s Wikipedia page, as well as adding a page for the global head of PR, Caryn Marooney.
In March 2019, the perpetrator of the Christchurch mosque shootings in New Zealand used Facebook to stream live footage of the attack as it unfolded. Facebook took 29 minutes to detect the livestreamed video, which was eight minutes longer than it took police to arrest the gunman. About 1.3m copies of the video were blocked from Facebook but 300,000 copies were published and shared. Facebook has promised changes to its platform; spokesman Simon Dilner told Radio New Zealand that it could have done a better job. Several companies, including the ANZ and ASB banks, have stopped advertising on Facebook after the company was widely condemned by the public. Following the attack, Facebook began blocking white nationalist, white supremacist, and white separatist content, saying that they could not be meaningfully separated. Previously, Facebook had only blocked overtly supremacist content. The older policy had been condemned by civil rights groups, who described these movements as functionally indistinct. Further bans were made in mid-April 2019, banning several British far-right organizations and associated individuals from Facebook, and also banning praise or support for them.
In early-April 2019, Facebook announced that it would be pulling its apps from Windows Phone on April 30, 2019, including Facebook, Messenger and Instagram.
NTJ's member Moulavi Zahran Hashim, a radical Islamist imam believed to be the mastermind behind the 2019 Sri Lanka Easter bombings, preached on a pro-ISIL Facebook account, known as "Al-Ghuraba" media.
In May 2019, Facebook founded Libra Networks, reportedly in order to develop their own stablecoin cryptocurrency. In recent developments it has been reported that Libra is being supported by financial companies like Visa, Mastercard, PayPal and Uber. The consortium of companies is expected to pool in $10 million each to fund the launch of the cryptocurrency coin named Libra.
On May 2, 2019 at F8, the company announced its new vision with the tagline "the future is private". A redesign of the website and mobile app was introduced, dubbed as "FB5". The event also featured plans for improving groups, a dating platform, end-to-end encryption on its platforms, and allowing users on Messenger to communicate directly with WhatsApp and Instagram users.
On July 3, 2019, Facebook's option to view and load pictures stopped working as people around the world complained. Facebook posted on Twitter about the issue and said they would resolve it as soon as they could.
On July 31, 2019, Facebook announced a partnership with University of California, San Francisco to build a non-invasive, wearable device that lets people type by simply imagining themselves talking.
On September 5, 2019, Facebook launched Facebook Dating in the United States. This new application will allow users to integrate their Instagram posts in their dating profile.
Mark Zuckerberg (Chairman and Chief Executive Officer)
Sheryl Sandberg (Chief Operating Officer)
Mike Schroepfer (Chief Technology Officer)
David Wehner (Chief Financial Officer)
As of December 31, 2018, Facebook had 35,587 employees.
Board of directors
In April 2019, Facebook nominated Peggy Alford to be added as a board member during the May 2019 AGM. If this happens, she will become the first African-American woman to serve in this board, and the second African-American ever to do so. As of April 2019, Facebook's board consists of the following directors;
Mark Zuckerberg (Chairman, Founder and CEO)
Sheryl Sandberg (Executive Director and COO)
Marc Andreessen (Non-Executive Director, Co-Founder and General Partner, Andreessen Horowitz)
Erskine Bowles (Non-Executive Director, President Emeritus, University of North Carolina)
Kenneth Chenault (Non-Executive Director, Chairman and Managing Director, General Catalyst)
Susan Desmond-Hellmann (Non-Executive Director, CEO, Bill & Melinda Gates Foundation)
Reed Hastings (Non-Executive Director, Chairman, Co-Founder and CEO, Netflix)
Peter Thiel (Non-Executive Director, Co-Founder and Former CEO, PayPal, Founder and President, Clarium Capital)
Jeffrey Zients (Non-Executive Director, Former Director, U.S. National Economic Council)
(in millions US$)
Year Revenue Growth
2004 $0.4 —
2005 $9 2150%
2006 $48 433%
2007 $153 219%
2008 $280 83%
2009 $775 177%
2010 $2,000 158%
2011 $3,711 86%
2012 $5,089 37%
2013 $7,872 55%
2014 $12,466 58%
2015 $17,928 44%
2016 $27,638 54%
2017 $40,653 47%
2018 $55,013 38%
Facebook ranked No. 76 in the 2018 Fortune 500 list of the largest United States corporations by revenue. Most comes from advertising. One analysis of 2017 data determined that the company earned US$20.21 per user from advertising.
Significant revenue comes from bulk data access sold to the third parties.
Chart of Facebook's stock
Number of advertisers
In February 2015, Facebook announced that it had reached two million active advertisers with most of the gain coming from small businesses. An active advertiser is an advertiser that has advertised on the Facebook platform in the last 28 days. In March 2016, Facebook announced that it reached three million active advertisers with more than 70% from outside the US. Prices for advertising follow a variable pricing model based on ad auction bids, potential engagement levels of the advertisement itself. Similar to other online advertising platforms like Google and Twitter, targeting of advertisements is one of the chief merits of advertising visa a vis traditional mass advertising modes like television and print. Marketing on Facebook is employed through two methods based on the surfing habits, likes and shares, and purchasing data of the audience, namely targeted audiences and "look alike" audiences.
Mergers and acquisitions
Main article: List of mergers and acquisitions by Facebook
Facebook's major acquisitions include Instagram, WhatsApp and Oculus Rift.
Users outside of the US and Canada contract with Facebook's Irish subsidiary "Facebook Ireland Limited". This allows Facebook to avoid US taxes for all users in Europe, Asia, Australia, Africa and South America. Facebook is making use of the Double Irish arrangement which allows it to pay just about 2–3% corporation tax on all international revenue. In 2010, Facebook opened its fourth office, in Hyderabad and the first in Asia.
Facebook's Hyderabad center houses online advertising and developer support teams and provide support to users and advertisers. In India Facebook is registered as 'Facebook India Online Services Pvt Ltd'. It also has support centers in Dublin, California, Ireland and Austin, Texas.
Facebook opened its London headquarters in 2017 in Fitzrovia in central London. Facebook opened an office in Cambridge, Massachusetts in 2018. The offices were initially home to Facebook's "Connectivity Lab", a group focused on bringing Internet access those who do not have access to the Internet.
Entrance to Facebook's previous headquarters in the Stanford Research Park, Palo Alto, California
Entrance to Facebook headquarters complex in Menlo Park, California
Inside the Facebook headquarters in 2014
As of 2019 the company operated 15 data center locations. Facebook committed to purchase 100 percent renewable energy and reduce our greenhouse gas emissions by 75 percent by 2020. Data center technologies include Fabric Aggregator, a distributed network system that accommodates larger regions and varied traffic patterns.
The StatePoint Liquid Cooling (SPLC) system is an evaporative cooling system that uses water to drive cooling.
See also: Corporation tax in the Republic of Ireland § Multinational tax schemes, and Double Irish arrangement § Effect of Tax Cuts and Jobs Act
The US IRS challenged the valuation Facebook used when it transferred IP from the US to Facebook Ireland in 2010 (which Facebook Ireland then revalued higher before charging out), as it was building its double Irish tax structure. The case is ongoing and Facebook faces a potential fine of $3–5bn.
The US Tax Cuts and Jobs Act of 2017 changed Facebook's global tax calculations. Facebook Ireland is subject to the US GILTI tax of 10.5% on global intangible profits (i.e. Irish profits). On the basis that Facebook Ireland is paying some tax, the effective minimum US tax for Facebook Ireland will be circa 11%. In contrast, Facebook Inc. would incur a special IP tax rate of 13.125% (the FDII rate) if its Irish business relocated to the US. Tax relief in the US (21% vs. Irish at the GILTI rate) and accelerated capital expensing, would make this effective US rate around 12%.
The insignificance of the US/Irish tax difference was demonstrated when Facebook moved 1.5bn non-EU accounts to the US to limit exposure to GDPR.
Main articles: List of Facebook features and Facebook Platform
Profile shown on Thefacebook in 2005
Previous Facebook logo in use from August 23, 2005 until July 1, 2015
The website's primary color is blue as Zuckerberg is red–green colorblind, a realization that occurred after a test undertaken around 2007 Facebook is built in PHP, compiled with HipHop for PHP, a "source code transformer" built by Facebook engineers that turns PHP into C++. The deployment of HipHop reportedly reduced average CPU consumption on Facebook servers by 50%.
Facebook is developed as one monolithic application. According to an interview in 2012 with Chuck Rossi, a build engineer at Facebook, Facebook compiles into a 1.5 GB binary blob which is then distributed to the servers using a custom BitTorrent-based release system. Rossi stated that it takes about 15 minutes to build and 15 minutes to release to the servers. The build and release process has zero downtime. Changes to Facebook are rolled out daily.
Facebook used a combination platform based on HBase to store data across distributed machines. Using a tailing architecture, events are stored in log files, and the logs are tailed. The system rolls these events up and writes them to storage. The user interface then pulls the data out and displays it to users. Facebook handles requests as AJAX behavior. These requests are written to a log file using Scribe (developed by Facebook).
Data is read from these log files using Ptail, an internally built tool to aggregate data from multiple Scribe stores. It tails the log files and pulls data out. Ptail data are separated into three streams and sent to clusters in different data centers (Plugin impression, News feed impressions, Actions (plugin + news feed)). Puma is used to manage periods of high data flow (Input/Output or IO). Data is processed in batches to lessen the number of times needed to read and write under high demand periods (A hot article generates many impressions and news feed impressions that cause huge data skews). Batches are taken every 1.5 seconds, limited by memory used when creating a hash table.
Data is then output in PHP format. The backend is written in Java. Thrift is used as the messaging format so PHP programs can query Java services. Caching solutions display pages more quickly. The data is then sent to MapReduce servers where it is queried via Hive. This serves as a backup as the data can be recovered from Hive.
On March 20, 2014, Facebook announced a new open-source programming language called Hack. Before public release, a large portion of Facebook was already running and "battle tested" using the new language.
Facebook uses the Momentum platform from Message Systems to deliver the enormous volume of emails it sends to its users every day.
On July 20, 2008, Facebook introduced "Facebook Beta", a significant redesign of its user interface on selected networks. The Mini-Feed and Wall were consolidated, profiles were separated into tabbed sections, and an effort was made to create a cleaner look. Facebook began migrating users to the new version in September 2008.
User profile/personal timeline
Facebook login/signup screen
Each registered user on Facebook has a personal profile that shows their posts and content. The format of individual user pages was revamped in September 2011 and became known as "Timeline", a chronological feed of a user's stories, including status updates, photos, interactions with apps and events. The layout let users add a "cover photo". Users were given more privacy settings. In 2007, Facebook launched Facebook Pages for brands and celebrities to interact with their fanbase. 100,000 Pages launched in November. In June 2009, Facebook introduced a "Usernames" feature, allowing users to choose a unique nickname used in the URL for their personal profile, for easier sharing.
In February 2014, Facebook expanded the gender setting, adding a custom input field that allows users to choose from a wide range of gender identities. Users can also set which set of gender-specific pronoun should be used in reference to them throughout the site. In May 2014, Facebook introduced a feature to allow users to ask for information not disclosed by other users on their profiles. If a user does not provide key information, such as location, hometown, or relationship status, other users can use a new "ask" button to send a message asking about that item to the user in a single click.
Main article: News Feed
News Feed appears on every user's homepage and highlights information including profile changes, upcoming events and friends' birthdays. This enabled spammers and other users to manipulate these features by creating illegitimate events or posting fake birthdays to attract attention to their profile or cause. Initially, the News Feed caused dissatisfaction among Facebook users; some complained it was too cluttered and full of undesired information, others were concerned that it made it too easy for others to track individual activities (such as relationship status changes, events, and conversations with other users). Zuckerberg apologized for the site's failure to include appropriate privacy features. Users then gained control over what types of information are shared automatically with friends. Users are now able to prevent user-set categories of friends from seeing updates about certain types of activities, including profile changes, Wall posts and newly added friends.
On February 23, 2010, Facebook was granted a patent on certain aspects of its News Feed. The patent covers News Feeds in which links are provided so that one user can participate in the activity of another user. The sorting and display of stories in a user's News Feed is governed by the EdgeRank algorithm.
The Photos application allows users to upload albums and photos. Each album can contain 200 photos. Privacy settings apply to individual albums. Users can "tag", or label, friends in a photo. The friend receives a notification about the tag with a link to the photo. This photo tagging feature was developed by Aaron Sittig, now a Design Strategy Lead at Facebook, and former Facebook engineer Scott Marlette back in 2006 and was only granted a patent in 2011.
On June 7, 2012, Facebook launched its App Center to help users find games and other applications.
On May 13, 2015, Facebook in association with major news portals launched "Instant Articles" to provide news on the Facebook news feed without leaving the site.
In January 2017, Facebook launched Facebook Stories for iOS and Android in Ireland. The feature, following the format of Snapchat and Instagram stories, allows users to upload photos and videos that appear above friends' and followers' News Feeds and disappear after 24 hours.
On October 11, 2017, Facebook introduced the 3D Posts feature to allow for uploading interactive 3D assets. On January 11, 2018, Facebook announced that it would change News Feed to prioritize friends/family content and de-emphasize content from media companies.
Main article: Facebook like button
Human billboard advertising Facebook Canberra in the City page at the National Multicultural Festival
The "like" button, stylized as a "thumbs up" icon, was first enabled on February 9, 2009, and enables users to easily interact with status updates, comments, photos and videos, links shared by friends, and advertisements. Once clicked by a user, the designated content is more likely to appear in friends' News Feeds. The button displays the number of other users who have liked the content. The like button was extended to comments in June 2010. Facebook expanded Like into "Reactions", choosing among five pre-defined emotions, including "Love", "Haha", "Wow", "Sad", or "Angry".
Main article: Facebook Messenger
Facebook Messenger is an instant messaging service and software application. It began as Facebook Chat in 2008, was revamped in 2010 and eventually became a standalone mobile app in August 2011, while remaining part of the user page on browsers.
Complementing regular conversations, Messenger lets users make one-to-one and group voice and video calls. Its Android app has integrated support for SMS and "Chat Heads", which are round profile photo icons appearing on-screen regardless of what app is open, while both apps support multiple accounts, conversations with optional end-to-end encryption and "Instant Games". Some features, including sending money and requesting transportation, are limited to the United States. In 2017, Facebook added "Messenger Day", a feature that lets users share photos and videos in a story-format with all their friends with the content disappearing after 24 hours; Reactions, which lets users tap and hold a message to add a reaction through an emoji; and Mentions, which lets users in group conversations type @ to give a particular user a notification.
Businesses and users can interact through Messenger with features such as tracking purchases and receiving notifications, and interacting with customer service representatives. Third-party developers can integrate apps into Messenger, letting users enter an app while inside Messenger and optionally share details from the app into a chat. Developers can build chatbots into Messenger, for uses such as news publishers building bots to distribute news. The M virtual assistant (U.S.) scans chats for keywords and suggests relevant actions, such as its payments system for users mentioning money. Group chatbots appear in Messenger as "Chat Extensions". A "Discovery" tab allows finding bots, and enabling special, branded QR codes that, when scanned, take the user to a specific bot.