A record of the blockchain’s state at a specific block or point in time. In other words, it is like a “photograph” of token balances across wallets at a certain moment.
Snapshots are commonly used for:
Airdrops: to determine who is eligible for free tokens, e.g. everyone who help X tokens in block #123456.
Forks: to allocate coins in both the old and new chains.
Governance: to ensure only eligible token holders — those who had tokens before the vote — can participate, preventing manipulation by late buyers.