A valid block that loses a temporary race and is not part of the most-work chain.
Stale block is best understood as part of a system rather than as an isolated definition. Its related coordinates show the mechanisms, incentives and historical records that give the term practical meaning.
Stale block sits between protocol rules, economic incentives and software operated by independent participants. In Bitcoin, no component is authoritative by itself: miners propose history, fully validating nodes enforce validity, and users decide which rules and software they accept.
Understanding Stale block helps distinguish a verifiable Bitcoin mechanism or historical record from slogans, products and market narratives.
For the clearest picture, read this entry together with Block, Chain reorganization, Mining. The reverse links also lead from Chain reorganization, Selfish mining, Block propagation, Compact block relay.
Linked to related atlas coordinates
Grounded in a source record
Explains function and trade-offs
Part of the open Bitcoin knowledge graph