Social media

Social media are new media technologies that facilitate the creation, sharing and aggregation of content (such as ideas, interests, and other forms of expression) amongst virtual communities and networks. Common features include:

The term social in regard to media suggests platforms enable communal activity. Social media enhances and extends human networks. Users access social media through web-based apps or custom apps on mobile devices. These interactive platforms allow individuals, communities, businesses, and organizations to share, co-create, discuss, participate in, and modify user-generated or self-curated content. Social media is used to document memories, learn, and form friendships. They may be used to promote people, companies, products, and ideas. Social media can be used to consume, publish, or share news.

Social media platforms can be categorized based on their primary function.

Popular social media platforms with over 100 million registered users include Twitter, Facebook, WeChat, ShareChat, Instagram, Pinterest, QZone, Weibo, VK, Tumblr, Baidu Tieba, Threads and LinkedIn. Depending on interpretation, other popular platforms that are sometimes referred to as social media services include YouTube, Letterboxd, QQ, Quora, Telegram, WhatsApp, Signal, LINE, Snapchat, Viber, Reddit, Discord, and TikTok. Wikis are examples of collaborative content creation.

Social media outlets differ from old media (e.g. newspapers, TV, and radio broadcasting) in many ways, including quality, reach, frequency, usability, relevancy, and permanence. Social media outlets operate in a dialogic transmission system (many sources to many receivers) while traditional media operate under a monologic transmission model (one source to many receivers). For instance, a newspaper is delivered to many subscribers, and a radio station broadcasts the same programs to a city.

Social media has been criticized for a range of negative impacts on children and teenagers, including exposure to inappropriate content, exploitation by adults, sleep problems, attention problems, feelings of exclusion, and various mental health maladies. Social media has also received criticism as worsening political polarization and undermining democracy, exacerbated by platform capture by vested interests, with journalist Maria Ressa deeming it "toxic sludge" for increasing distrust among members of society. Major news outlets often have strong controls in place to avoid and fix false claims, but social media's unique qualities bring viral content with little to no oversight. "Algorithms that track user engagement to prioritize what is shown tend to favor content that spurs negative emotions like anger and outrage. Overall, most online misinformation originates from a small minority of "superspreaders," but social media amplifies their reach and influence."

The PLATO system was launched in 1960 at the University of Illinois and subsequently commercially marketed by Control Data Corporation. It offered early forms of social media features with innovations such as Notes, PLATO's message-forum application; TERM-talk, its instant-messaging feature; Talkomatic, perhaps the first online chat room; News Report, a crowdsourced online newspaper, and blog and Access Lists, enabling the owner of a note file or other application to limit access to a certain set of users, for example, only friends, classmates, or co-workers.

ARPANET, which came online in 1969, had by the late 1970s enabled exchange of non-government/business ideas and communication, as evidenced by the network etiquette (or "netiquette") described in a 1982 handbook on computing at MIT's Artificial Intelligence Laboratory. ARPANET evolved into the Internet in the 1990s. Usenet, conceived by Tom Truscott and Jim Ellis in 1979 at the University of North Carolina at Chapel Hill and Duke University, was the first open social media app, established in 1980.