Decentralized applications—also known as 'dApps' or 'dapps' —are digital applications that run on a blockchain network of computers instead of relying on a single computer.

Dapps have their backend code (smart contracts) running on a decentralized network and not a centralized server. They use the Ethereum blockchain for data storage and smart contracts for their app logic. A smart contract is like a set of rules that live on-chain for all to see and run exactly according to those rules. Imagine a vending machine: if you supply it with enough funds and the right selection, you'll get the item you want. And like vending machines, smart contracts can hold funds much like your Ethereum account. This allows code to mediate agreements and transactions.