# Cache

> [HTML Version](cache.htm)

_Written August 2023_

The concept of caching, storing of local copies of files to speed up repeated references, occurs in a variety of places and flavors within A-Shell and ATE. Although the details vary, the common goal is to improve performance by storing local or memory copies of files previously retrieved from a more costly, time-consuming or distant resource. A common operational feature is that they are automatically checked prior to retrieving / opening a file, whether specified explicitly or implicitly.

See the subtopics listed below for details on the various types, names and functions of the cacheing systems used within A-Shell.

**See Also**

•	[Cacheing SBX Subroutines](loadingandcacheing.md)

•	[WEBCACHE setting in SET.LIT](webcache_in_set_lit.md)

**Subtopics**

- [ATEPERMCACHE](atepermcache.md)

- [ATECACHE](atecache.md)

- [ASWCACHE](aswcache.md)

- [WEBCACHE](webcache.md)