Learn · Lesson 1
What crypto is.
Crypto is a shared record of who owns what. That record is called a blockchain. Thousands of computers keep identical copies of it, so no single company can quietly change it.
The parts
- Blockchain A ledger made of blocks. Each block lists transactions and links to the block before it.
- Coin The native unit of a blockchain, such as BTC on Bitcoin, ETH on Ethereum, or SOL on Solana. It is also used to pay network fees.
- Token A unit created on top of a blockchain by an app or issuer. A stablecoin like USDC is a token.
- Wallet Software or a device that holds the keys that control your coins and tokens.
- Network The computers that check and agree on new transactions, using rules such as proof of work or proof of stake.
Why it matters
On a public blockchain, anyone can check the record, and the person holding the keys controls the asset. That is different from a bank or app account, where the company keeps the record.
What it is not
Crypto is not a guaranteed way to make money. Prices move a lot, and transactions usually cannot be reversed. This lesson only explains how it works.
Next
Lesson 2: Wallets · Back to the Learn hub
Sources
- How a blockchain and proof of work fit together: Bitcoin whitepaper (bitcoin.org)
- Proof of stake on Ethereum: ethereum.org
- USDC as a token: circle.com/usdc
Sources · checked Oct 8, 2026