Cache Coherency

Cache coherency is a system ensuring that multiple copies of data stored temporarily (caches) in different parts of a computing system stay consistent. When several processors or cores access shared data, they each keep a local cache for faster access. Without maintaining coherency, these caches could hold outdated or conflicting data. Cache coherency protocols manage updates so that when one cache modifies data, all other caches see the change, preventing errors and ensuring the system operates correctly. Essentially, it keeps all copies synchronized, maintaining data integrity across the system.