Web3 is simply the name given to the next iteration of the internet that will consist of applications built on a blockchain. Web1 (approx. 1990–2005) was the infancy stage of the internet, defined by static pages where users primarily consumed content.
Web2 (approx. 2005–2020) saw the rise of interactive websites, allowing users to upload their own content, connect with others and actively participate. The pitfall of web2 was its centralization, with most of the value created by users being monetized by the likes of Google, Amazon and Facebook, resulting in a disproportionate distribution of value.
Web3 will be an open, decentralized and community-governed network owned by builders and users, powered by cryptocurrencies. Where web1 favored publishers and web2 favored platforms, web3 favors users and value creators.