Learn crypto, step by step
Short, plain-English lessons. Start at the top and work down, or jump to what you need.
BeginnerWhat is cryptocurrency?
Cryptocurrency is digital money that runs on a public network instead of a bank. No single company controls it. Thousands of computers around the world keep a shared record of who owns what.
Bitcoin launched in 2009 as the first one. Today there are thousands of coins and tokens, each built for a different purpose: payments, apps, games, stablecoins and more.
- Digital: it exists only as entries on a network.
- Decentralized: no bank or government runs it.
- Scarce by design: many coins have a fixed or predictable supply.
Key takeaway: Crypto is digital money secured by math and kept honest by a global network rather than a bank.
BeginnerHow does a blockchain work?
A blockchain is a shared ledger, like a notebook that everyone has a copy of. New transactions are grouped into a “block”, checked by the network, and added to the end of the chain.
Every block links to the one before it. Changing an old record would mean redoing every block after it on most of the network at once, which is what makes blockchains so hard to tamper with.
- Blocks hold batches of transactions.
- Each block links to the previous one with a cryptographic hash.
- Validators (miners or stakers) agree on which blocks are valid.
Key takeaway: A blockchain is a tamper-resistant shared record that no single person controls.
BeginnerWallets & keys: who really owns your coins?
A crypto wallet doesn't hold coins. It holds the keys that prove you own them. Your public address is like an email address you can share, and your private key (or seed phrase) is like the password.
If you keep your coins on an exchange, the exchange holds the keys for you (“custodial”). With a self-custody wallet, you hold them yourself.
- Never share your seed phrase. No real support team will ever ask for it.
- Write your seed phrase on paper and store it offline.
- Hardware wallets keep your keys off the internet.
Key takeaway: “Not your keys, not your coins.” Guard your seed phrase like cash.
BeginnerBitcoin vs Ethereum
Bitcoin is built mainly to be digital money and a store of value. Its supply is capped at 21 million coins.
Ethereum is a programmable blockchain. Developers use it to build apps (“smart contracts”) for things like DeFi, NFTs and stablecoins. ETH is the fuel that pays for using those apps.
- BTC: digital gold, fixed supply.
- ETH: a world computer for apps.
- Both are secured by large global networks.
Key takeaway: Think of Bitcoin as digital gold and Ethereum as the platform for crypto apps.
IntermediateStablecoins explained
Stablecoins are tokens designed to hold a steady price, usually $1. Most are backed by cash and short-term government bonds held by the issuer.
They let people move dollars on blockchains quickly, at any hour and across borders. Traders also use them to step out of volatile coins without leaving crypto.
- Fiat-backed: reserves held by a company (e.g. USDC, USDT).
- Crypto-backed: over-collateralized with other crypto.
- Always check who backs a stablecoin and how.
Key takeaway: A stablecoin is only as stable as the reserves and the issuer behind it.
EssentialStaying safe: spotting scams
Crypto transactions can't be reversed, and that is exactly why scammers love them. Most losses come from tricks, not hacks.
Watch for: guaranteed returns, “double your crypto” giveaways, fake support accounts in your DMs, urgent pressure to act now, and links that look almost like the real site.
- If it sounds too good to be true, it is.
- Bookmark real sites and use only those.
- Turn on 2FA with an app, not SMS.
- Test with a small amount before big transfers.
Key takeaway: Slow down. Urgency is a scammer's favorite tool.
IntermediateReading the market: price, market cap & volume
Price alone tells you little. Market cap (price × circulating supply) shows a coin's total value, and that's how coins are ranked.
Volume shows how much traded in the last 24 hours. A high volume means a liquid market, while a low volume means prices can swing more easily.
- A $0.01 coin isn't “cheap” if it has trillions of tokens.
- Compare market caps, not prices.
- Check 7-day change, not just 24 hours, for context.
Key takeaway: Market cap tells you size; volume tells you activity; price alone tells you very little.
