Definition: A tactic where attackers send small transactions to make a fake address appear in your history. Example: You copy an address from history and accidentally send funds to the attacker.

Definition: Malware that changes copied addresses before you paste them. Example: You copy your own address, paste it, and it silently becomes a different one.

Definition: Permission you grant to a smart contract to move your tokens. Example: A swap requires approval before the contract can spend your tokens.

Definition: Removing previously granted token permissions to reduce ongoing risk. Example: After using a dApp once, you revoke its allowance so it can’t spend later.

Definition: A second verification step beyond a password to protect accounts. Example: A login requires a code from an authenticator app.

Definition: Government-issued currency that isn’t backed by a physical asset but by trust in the issuing authority. Example: The Euro and the US Dollar are fiat currencies because their value comes from government backing and people’s trust.

Definition: A distributed digital ledger where transactions are recorded in blocks, linked together, and cannot be altered once confirmed. Example: Bitcoin’s blockchain shows every transaction ever made, publicly accessible via a block explorer.

Definition: The process of sending cryptocurrency from one wallet address to another, recorded on the blockchain. Example: Sending 0.01 BTC to a friend’s wallet address is a transaction.

Definition: A computer connected to the blockchain network that helps validate and relay transactions. Example: Thousands of Bitcoin nodes around the world keep the network decentralized and secure.

Definition: A participant in a blockchain network (especially Proof-of-Stake systems) that confirms transactions by staking tokens. Example: On Ethereum, validators stake ETH to confirm blocks and earn rewards.

Definition: A participant in Proof-of-Work blockchains that uses computing power to secure the network and validate transactions. Example: Bitcoin miners solve cryptographic puzzles to add blocks and receive BTC rewards.

Definition: The mechanism by which blockchain participants agree on the state of the ledger. Example: Bitcoin achieves consensus through Proof of Work, while Ethereum now uses Proof of Stake.