AOL Instant Messenger was launched in 1997 and MSN Messenger launched in 1999. These instant messaging platforms ushered in a new era of instant communication and laid the foundation for future social media platforms.
In 2003, MySpace launched, taking the world by storm until Facebook launched in 2004 and quickly usurped it. Reddit launched in 2005 and Twitter launched in 2006. Pinterest launched in 2010 along with Instagram and Quora.
Several platforms you probably used have lived and died. Vine, Bebo, Google+, Path and Periscope are prime examples. Today, the big social networks include Twitter, Facebook, Instagram, LinkedIn, Pinterest, Snapchat, TikTok and Quora.