The architecture of web3 is completely different. Here things are a little bit more complicated. The database and server are not centrally located. As we don’t have a centralized server, we can’t query data and perform all business logic. For this, we write something called smart contracts. These are pieces of code we write to communicate with the Ethereum blockchain. A virtual machine called Ethereum Virtual Machine (EVM) is in between, which executes our code.
Continue reading here: https://digiligo.com/blog/web-3-0-architecture/
