Blockchain
A distributed, immutable digital ledger that records transactions across a network of computers.
A blockchain is a database with special properties. Once data is written, it can't be changed. Every participant in the network has a copy, so there's no single point of failure. Transactions are grouped into blocks, and each block is cryptographically linked to the previous one, forming a chain.
For USDC, the blockchain is where ownership records live. When you send USDC to someone, the transaction is recorded on the blockchain forever. USDC exists on 29+ blockchains, and the token on each chain is backed by the same pool of reserves.
Different blockchains offer different trade-offs in speed, cost, and security. Ethereum is the most established but has higher fees. Base and Solana are faster and cheaper.
Related Terms
Layer 1 (L1)
The base blockchain network that processes and finalizes transactions on its own. Examples: Ethereum, Solana, Avalanche.
Layer 2 (L2)
A secondary network built on top of a Layer 1 blockchain to increase speed and reduce transaction costs. Examples: Base, Arbitrum, Optimism.
Smart Contract
Self-executing code deployed on a blockchain that automatically enforces the terms of an agreement.
Gas Fees
Transaction fees paid to blockchain validators for processing and confirming transactions.
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This definition is provided for educational purposes. USDC.org is an independent resource and is not affiliated with Circle Internet Financial.