Plain meaning
Start with the shortest useful explanation before going deeper.
The vision of a decentralized internet built on blockchain technology, where users own their data, identity, and digital assets. Web1 was read-only (static pages), Web2 is read-write (platforms like social media), Web3 is read-write-own (permissionless, user-sovereign). Web3 applications use wallets instead of logins and smart contracts instead of centralized servers.