What is Web3?

What the term describes

Web3 is a broad term for applications that use blockchains, wallets, and tokens. These systems can let users hold and transfer digital assets through accounts they control.

Accounts and ownership

A platform account and a blockchain account have different controls. A service manages access to its own records; a blockchain account authorizes actions through keys or contract rules. Uploading a photo to a platform does not, by itself, transfer its copyright to the platform.

Self-custody changes who can authorize transactions, but applications can still depend on companies, hosted services, or token issuers. Check those dependencies separately from ownership of the token itself.

Three phases of the internet

The internet changed twice before. We are in the middle of the third change.

Era	Years	What you could do	Who was in charge
Web1	1991-2004	Read websites	Nobody (open protocols)
Web2	2004-now	Read + write + share	Big platforms (Google, Meta, Amazon)
Web3	2015-now	Read + write + own	Users (through blockchains)

Web1 was like a library. You could read, but you could not write. Websites were static pages. If you wanted to publish, you needed to know HTML.

Web2 gave everyone a voice. Facebook, YouTube, and Twitter let anyone post. But the trade-off was big: these platforms collected your data and sold ads against it. You became the product.

Web3 adds on-chain accounts and assets to application design. Some tokens have issuer freeze controls, and some protocols can be upgraded by administrators or governance. These permissions should be examined before use.

The four building blocks

Web3 runs on four things. Each one is simple on its own.

Blockchains

A blockchain is a shared record book. Thousands of computers around the world each keep a copy. When someone sends money, every copy gets updated at the same time. No single person or company can change the records.

Ethereum is the most popular blockchain for building apps. Bitcoin was first but is mostly used for storing and sending money.

Smart contracts

A smart contract is a small program that lives on a blockchain. It runs by itself when certain conditions are met.

For example, a swap transaction calls a trading contract. The contract checks the input, calculates the output under its pricing rules, and either completes the exchange or reverts.

Wallets

A wallet is two things in one: your identity and your bank account. When you connect to a Web3 app, your wallet proves who you are. It also holds your money and tokens.

Popular wallets: MetaMask (browser), Phantom (Solana), Rabby (multi-chain). Hardware wallets like Ledger keep your keys on a physical device for extra safety.

Tokens

Tokens are digital units that represent something. A few common types:

• ETH - the currency of Ethereum, used to pay for transactions
• USDC - a stablecoin worth $1, backed by cash and US Treasury bonds
• UNI - a governance token that lets holders vote on how Uniswap works

What is different for you

If you are a...	Web2	Web3
User	Platform holds your data	You hold your data
Developer	Build on private APIs	Build on open protocols
Business	Revenue from ads	Revenue from protocol fees

For job seekers, requirements depend on the role. Some positions use familiar software, finance, or operations skills; others require protocol-specific experience. Read the qualifications in each listing rather than assume training is provided.

What Web3 does not do

Before using an application, consider:

• Most Web3 apps still use regular servers for speed. Only the important parts (money, ownership) go on-chain.
• If you lose your wallet password (called a seed phrase), your money is gone. There is no "forgot password" button.
• Transaction fees exist. Sending money on Ethereum costs a few dollars. Layer 2 networks bring this down to cents.
• Scams exist. If someone DMs you about a "special token," it is almost always a scam.