Web 2.0 is a term used to describe the post-dotcom bubble World Wide Web (or the very first version of the internet, known as Web 1.0), which places a strong emphasis on social networking (Facebook, Instagram, Snapchat, etc.), user-generated content, and cloud computing. The 2.0 designation is used to denote a new, enhanced version by making an analogy with standard computer program naming rules.
The phrase was first used in 2004 by publisher Tim O’Reilly to refer to a series of Web conferences. The elements of Web 2.0 grew commonplace and lost their novelty in the 2010s, which caused the term’s popularity to decline.