What Is Blockchain?

A blockchain is a decentralized database where transactions are grouped into blocks and linked together in a chain using cryptography. Each block contains a record of transactions, and once added, blocks cannot be altered without invalidating the entire chain. This immutability is critical for airdrop farming because it creates a permanent, verifiable record of your wallet activity, on-chain transactions, and eligibility criteria.

For airdrop farming specifically, the blockchain serves as the source of truth for snapshots. When a protocol like Arbitrum or Jito takes a snapshot to determine airdrop eligibility, they're reading your historical transactions directly from the blockchain ledger. Your token swaps on Uniswap, liquidity provided to pools, governance votes—all of this is permanently recorded on-chain. Protocols use this data to verify you actually used their network rather than just holding tokens.

Different blockchains have different properties that affect airdrop farming strategy. Layer 2 blockchains like Arbitrum and Optimism are cheaper to transact on, making it economical to farm smaller airdrops. The Solana blockchain processes transactions faster but has different gas dynamics. When planning airdrop farms, you choose blockchains based on cost efficiency and which protocols have announced or rumored airdrops on them.

Understanding blockchain mechanics matters because airdrop snapshots are permanent—they capture your wallet state at a specific block height. If you want to qualify for a retroactive airdrop on a new chain, you need to have interacted with protocols on that blockchain before the snapshot block. You can't retroactively create transaction history. This is why early testnet participation is valuable; testnet blockchains often determine mainnet airdrop eligibility.