Blockchain Glossary

Clear definitions for common terms such as addresses, blocks, gas, transaction hashes, EVM, Layer 2, DApps, approvals and validators.

Wallets and keys

Addresses can be public for receiving assets, while seed phrases and private keys are control credentials. Understanding public versus secret information is the first wallet-security boundary.

AddressA public identifier used to receive assets or identify an on-chain account. Verify the network even when the address format looks familiar.

Seed phraseA sensitive recovery phrase that should remain under your own custody, preferably offline.

Private keyA secret key capable of controlling an on-chain account. Never send it to another person.

BlockA data structure that records a batch of transactions in sequence on a blockchain.

Transactions and networks

Blocks, gas, transaction hashes and confirmations describe how activity enters a network. When status looks wrong, verify the network first and inspect the transaction hash on-chain.

Transaction hashAn identifier for an on-chain transaction that can be checked on the correct block explorer.

GasThe network-fee mechanism for submitting on-chain operations.

EVMEthereum Virtual Machine, a contract execution model used by many compatible networks.

Layer 2A scaling approach that processes activity beyond the base layer while relying on it for parts of settlement or security.

Web3 and scaling networks

DApps, approvals, NFTs, EVM and Layer 2 involve contracts and different network environments. Similar address formats do not make contracts or assets identical across networks.

DAppA decentralized application that interacts with a blockchain or smart contracts.

ApprovalAn on-chain permission allowing a contract to use a token within a specified allowance.

NFTA non-fungible token commonly represented by a unique token ID in a smart contract.

ValidatorA participant in a PoS network that may propose blocks, attest or perform other consensus duties.

PoS, validators and lookup tools

PoS and validators concern consensus and network participation, while bridges and block explorers support cross-network paths and on-chain lookup. Continue to verify domains and networks when using third-party tools.

PoSProof of Stake, a consensus mechanism based on staked value and validator participation.

BridgeA mechanism for moving assets or messages between networks or layers.

Block explorerA public tool for viewing addresses, transactions, blocks and contract data.

ConfirmationThe depth of a transaction after inclusion as additional blocks are added.

Learning method

Do not memorize definitions without knowing when to verify them

Apply the terms to real situations: receiving assets should prompt address and network checks; submitting a transaction should prompt gas and transaction-hash checks; DApp use should prompt signature and approval review; cross-layer activity should prompt Layer 2, bridge and destination-network checks; PoS should be considered together with validator status, changing rewards and penalty risk. The value of terminology is knowing what to verify next.

Wallet

Addresses, seed phrases and private keys

Network

Gas, blocks and confirmations

Web3