Cache consistency refers to the practice of ensuring that multiple copies of data stored in different caches remain synchronized. When data is updated in one cache, it is crucial that all other caches reflect this change to prevent discrepancies. This is particularly important in systems where multiple processors or users access shared data. There are various protocols, such as MESI and MOESI, designed to maintain cache consistency. These protocols help manage how data is read and written across caches, ensuring that all users see the most current version of the data. This consistency is vital for the reliability and accuracy of computing systems.