The Cache modules are designed to assist a developer in persisting
data for a specified period of time. Often these modules are used
in web applications to store data locally to save repeated and
redundant expensive calls to remote machines or databases.
The Cache interface is implemented by derived classes that store
cached data in different manners (such as as files on a filesystem,
or in memory).
To use the Cache system, a cache implementation must be chosen to
suit your needs. The most common is Cache::File, which is suitable
for sharing data between multiple invocations and even between
concurrent processes.
