Caching is the process of collecting duplicates of original data values, that are then stored (cached) in a location that is easier to access for enhanced performance.
The following are just a few examples of the different types of cache:
CPU cache—a small area of fast memory used by the central processing unit
Database cache—temporary storage of database content in multi-tier applications
Query cache—temporary storage of query data and metadata to increase performance
Web cache—temporary storage of web documents to increase performance