How Crypto Works: Cryptocurrency for Beginners

How crypto works is often explained with metaphors about digital gold or internet money. For anyone who already understands how a broker holds client funds, a more useful picture is this: a crypto network is a public accounting system, run by many computers that do not trust each other, that decides which address holds which balance and in what order transfers happened.

What is a blockchain actually recording?

Short answer: a list of transactions, grouped into blocks, each block linked to the previous one so that altering old records would require redoing all the work since.

Every participant running the network's software keeps a copy of the ledger. New transactions are broadcast to the network, collected into a block by whoever wins the right to add the next one, and accepted by everyone else once they check it follows the rules. On Bitcoin, that right is earned through proof of work, spending electricity to solve a puzzle. On Ethereum and many newer networks, it is assigned through proof of stake, where validators lock up coins as a deposit they lose if they cheat.

A "coin" is not a file that moves around. It is a balance recorded against an address in that shared ledger. Tokens are balances recorded by a smart contract running on a network such as Ethereum or Tron, which is how thousands of different assets can share one chain.

Who controls a crypto balance?

Whoever holds the private key. An address is derived from a public key, and only the matching private key can sign a transaction that spends from it. Wallet software stores that key for you and usually lets you back it up as a recovery phrase of 12 or 24 words. Anyone who sees that phrase can take the funds, which is why no genuine service will ever ask for it.

How crypto works when a transfer is sent

1. Your wallet builds a transaction naming the recipient address, the amount and a network fee, and signs it with your private key.
2. The transaction is broadcast and waits with others to be included in a block. A higher fee can mean faster inclusion when the network is busy.
3. Once in a block, it has one confirmation. Each later block adds another and makes reversal less practical. Platforms set their own number of confirmations before crediting a deposit.
4. After confirmation there is no chargeback, no bank to call and no cancel button. A mistyped address or a wrong network is usually a permanent loss.

That irreversibility is also what scammers rely on. Our guide to spotting trading scams covers the address-poisoning and fake-support tricks that exploit it.

How are coins priced and traded?

Most people buy crypto on a centralised platform that runs an order book, much like a stock exchange, but each platform is its own separate market. Prices are usually quoted against a stablecoin such as USDT or against a currency such as the dollar. Decentralised exchanges replace the order book with a pool of two tokens whose ratio sets the price, so large trades move the price against the trader, an effect called slippage.

Crypto trades every day of the year, and weekend liquidity can be thin. Swings that would be extraordinary in a major currency pair are common: an illustrative coin that falls 60% needs to rise 150% just to get back to where it started, because the gain is measured from the lower base.

Where do stablecoins fit in?

Short answer: a stablecoin tries to stay pinned to an outside value, most often a single US dollar, and serves as the cash side of most crypto trades.

Most large stablecoins are issued by a company that says it holds reserves, such as short-term government debt and cash, to back each token. Others try to hold their peg through over-collateralised crypto loans or through algorithms, and some algorithmic designs have collapsed completely. Our page on what USDT is looks at the largest one in detail.

A steady price is not the same as a safe yield. Be wary of anything sold as a "stable fund crypto" product that promises fixed monthly returns: the token may be designed to stay at a dollar, but the returns have to come from lending, trading or new deposits, and each of those can fail. Several such schemes have frozen withdrawals when markets turned.

What are smart contracts and decentralised finance?

A smart contract is a program stored on a blockchain that runs exactly as written when someone sends it a transaction. Ethereum made these programs widely available, and they now power token issuance, decentralised exchanges, lending pools and much more, collectively called decentralised finance, or DeFi. The attraction is that no company sits in the middle; the drawback is the same. If the code contains a flaw, funds can be drained, and there is usually no one to reimburse users. Approving a contract to spend your tokens is also a common route for theft, because a malicious contract can use that permission later.

Some DeFi platforms have been exploited repeatedly, and "audited" does not mean safe: an audit reviews code at a point in time and cannot rule out every weakness.

What records should I keep?

Keep a note of every purchase, sale, swap and transfer, with dates, amounts, prices and fees. Many tax authorities treat selling a coin, and often swapping one coin for another, as a taxable disposal, and platforms can close or lose their data. Your own records are also the first thing anyone will ask for if you need to report fraud or dispute a transaction.

What does a crypto trade cost?

Platform trading fees, the spread, network fees for transfers, withdrawal fees set by the platform and, when you buy with a card or convert currency, payment charges. Each looks small; together they can take several percent of a modest purchase. The crypto profit calculator shows the effect of a fee on each side of a trade, and our guide to trading fees lists the rest.

Which risks are easy to underestimate?

• Platform risk: coins left on a platform are only as safe as that firm's controls and honesty.
• Regulatory gaps: rules are tightening, but in many countries there is still no compensation scheme for crypto held with a failed firm.
• Leverage: in the UK, retail consumers cannot be sold crypto derivatives at all, and in the EU retail crypto CFDs are capped at 2:1. Offshore platforms offering far more are outside those protections.
• Operational mistakes: wrong network, wrong address, lost recovery phrase.

For the asset that started it all, continue with what Bitcoin is; before looking at long tables of coins, read how to interpret a cryptocurrency list price.

Sources

• UK Financial Conduct Authority, ban on crypto-derivatives for retail consumers
• European Securities and Markets Authority, product intervention measures on CFDs
• Bitcoin and Ethereum protocol documentation