When we talk about Web3, we are referring to the set of technologies that are transforming the Internet in pursuit of greater decentralization.
The technology behind Web3 is DLT - that is, the technology on which cryptocurrencies and NFTs are also based (see What is blockchain, DLT and what supports the authenticity of an NFT?).
DLTs are networks without the centralized control of a company or government. Indeed, with Web3, content is not concentrated on large platforms and it is more difficult for the network to suffer any kind of attack.
Because of the advantages it brings, creators and users are interested in the advancement of Web3. There are also startups and companies that have also paid attention to initiating or promoting the transition from Web2 to Web3.