Apple AppleShare IP 5.0 Update - Manual (Page 17)

The Web & File Server cache is a portion of random-access memory (RAM)
that the File Server uses for storing frequently used files, folders, and icons.
By caching items in RAM, the File Server provides faster access to shared
items than if they were retrieved from the computer’s hard disk.
The following illustration shows how RAM is apportioned in a computer that
runs the Web & File Server.
Total RAM
System
software
Web & File Server
uses available RAM
as needed
Web & File
Server
program Reserved RAM Available RAM
Memory reserved for
other programs (as set
in the Cache view of the
Web & File Server
Settings window) Programs started
prior to starting the
Web & File Server
Appendix C Web & File Server Cache