The main differences between Web 2.0 Web 3.0

Web 2.0: Centralized Platforms

Web 3.0: Decentralized Protocols
The best example of the difference between Web 2 and Web 3 is a comparison of Coinbase and Uniswap. Coinbase is the brainchild of Web 2 crypto; Uniswap is the epitome of Web 3. Coinbase is a company that operates a centralized exchange and order book that stores cryptocurrency on behalf of its users. It charges a transaction fee and retains 100% of its revenue. Uniswap, on the other hand, is a protocol, not a company. It provides a decentralized exchange service and does so without withholding customer funds. Like Coinbase, Uniswap charges a transaction fee, but 100% of its revenue goes to liquidity providers, not Uniswap.

Web 2.0: Off-chain tx
Off-chain transactions are any transactions processed outside the blockchain

Web 3.0: On-chain tx
On-chain transactions are what we usually call blockchain transactions. It is the most popular of the two types of transactions, requiring a general update of the blockchain network.
For a transaction on the network to be completed, the miners must receive an agreed number of confirmations.