Web3
What Is Web3?
Web3 is the idea that, with blockchain technology, you can become responsible for holding your own data, money, or identity, without having to rely totally on centralized entities.
On the internet most people grew up with, comparatively called Web2, a platform’s database decides what you own. A bank can freeze your account, and a social app can delete your profile, and there is often little recourse if either happens.
Web3 proposes a different structure: instead of a username and password tied to someone else’s server, you access services with a wallet address tied to a private key that only you hold. Ownership becomes something the network verifies, not something a company grants you.
How Does the Web3 Idea Work in Practice?
Putting this idea into practice starts with your wallet. Instead of a username and password, a wallet address tied to a private key becomes your way to access applications built this way, and only you hold the key that authorizes what happens with it.
Many Web3 applications use smart contracts for important rules and operations instead of a company’s private database (though they may host some components off-chain). A smart contract executes automatically once its conditions are met, so the rules of an app can be visible and independently verified on the blockchain rather than hidden inside a corporate backend. That structure lets you interact directly with a piece of software, or with another person, without a traditional intermediary sitting in the middle to approve each onchain transaction.
Self-custody covers the ownership half of that structure, holding your own keys instead of trusting a company to hold assets for you. DeFi and dApps put the mechanism to work as financial tools and software you interact with directly.
Each of these terms answers a piece of the same question Web3 first raised: who controls your data and your assets once they move onchain.