Glossary

A digital ledger made of linked, cryptographically-sealed blocks, copied across many independent computers so no single party controls it.

A bundle of transactions plus a timestamp and the previous block's hash, sealed together and added to the chain.

Running data through a one-way function that produces a fixed-length fingerprint. Change one character of the input and the output changes completely.

Any computer running the blockchain's software and keeping a copy of the ledger, helping verify and relay transactions.

A participant in a Proof of Work network who spends computing power competing to add the next block, earning a reward for the winning attempt.

A participant in a Proof of Stake network who locks up ("stakes") the network's asset as collateral in exchange for the right to propose or confirm blocks.

A consensus method where adding a block requires expensive computation, making it costly to attack the network but cheap for others to verify.

A consensus method where the right to add blocks depends on staked collateral rather than computing power, with dishonest behavior punished by losing part of that stake.

The rulebook a network uses to agree on which version of the ledger is the valid one, without a central referee.

Software or hardware that stores your keys and lets you sign transactions — it doesn't literally hold coins, since those live on the ledger.

The secret credential that authorizes spending from an address. Anyone who has it controls the funds — never share it.

The shareable identifier derived from your private key, used to receive funds — similar in spirit to a bank account number.

Code stored and executed on a blockchain, running automatically when its conditions are met, without a company enforcing it manually.

The fee paid to the network to process a transaction or run a smart contract, roughly proportional to how much computation is involved.

Financial applications — lending, trading, borrowing — built from smart contracts instead of banks or brokerages.

A token representing ownership of a specific, unique item or piece of data on-chain, as opposed to interchangeable units like a coin.

A cryptocurrency designed to hold a steady value, typically pegged to a fiat currency like the US dollar via reserves or algorithms.

Any cryptocurrency other than Bitcoin — a broad category spanning serious infrastructure projects to purely speculative tokens.

A split in a blockchain's rules or history, either a minor software upgrade (soft fork) or a permanent divergence into two separate chains (hard fork).

Keeping private keys entirely offline — on a hardware device or even paper — so they're never exposed to an internet-connected system.

A platform that matches buyers and sellers and typically provides an on-ramp between traditional currency and crypto.

A scenario where one party gains control of the majority of a network's mining power or staked value, potentially letting them rewrite very recent transaction history.

Current price multiplied by circulating supply — a rough measure of an asset's total market value, not a guarantee of liquidity.

How sharply and quickly an asset's price moves. Crypto markets tend to show higher volatility than most traditional asset classes.

A technical document a project publishes explaining what it does, how it works, and the reasoning behind its design — Bitcoin's, published by Satoshi Nakamoto in 2008, is the field's founding example.