The Networked World: Social Media to the Cloud

Early social networking services, such as SixDegrees.com in 1997 and Friendster in 2002, experimented with connecting people online through profiles and lists of friends, but it was Facebook, founded by Mark Zuckerberg with fellow Harvard University students Eduardo Saverin, Dustin Moskovitz, and Chris Hughes in February 2004, that came to dominate the category. Initially restricted to Harvard students and then gradually opened to other universities, Facebook became available to the general public in September 2006 and reached one billion monthly active users by October 2012, a milestone reflecting how central the platform had become to everyday communication for a large share of the world's internet users. Twitter, launched in 2006 by Jack Dorsey, Biz Stone, Evan Williams, and Noah Glass, offered a different model built around short public posts, originally limited to 140 characters, that proved influential in real-time news distribution, political organizing, and public discourse, including a documented role in movements such as the Arab Spring uprisings beginning in 2010 and 2011. As these and other platforms, including Instagram, founded in 2010 and acquired by Facebook in 2012, and later TikTok, grew to reach billions of users worldwide, they reshaped how societies form communities, consume news, and conduct political and commercial life, while also drawing growing scrutiny over misinformation, data privacy, and their effects on mental health, particularly among younger users.