Definition
A checkpoint in blockchain is a designated block or state marker that the protocol treats as a reference point for the chain’s progress and security. It is a system-level component used to mark specific blocks or states as notable for consensus, coordination, or validation purposes, often constraining how far the canonical chain can be reconsidered or reorganized by the network.
In Simple Terms
A checkpoint is a special block or state that the blockchain protocol marks as an important reference point. The network uses it to keep track of progress and to limit how much of the chain can be changed later, helping participants coordinate around a shared view of which part of the chain is firmly established.
Context and Usage
The term checkpoint is commonly used in discussions of consensus design, chain stability, and protocol safety. It often appears in relation to how networks bound potential reorg depth, how validators coordinate around shared state, and how finality is expressed or approximated across epochs. Checkpoints are typically referenced in protocol specifications, client implementations, and security analyses of chain behavior.