At the core of the concept of the Ehcache API are three classes:

A CacheManager provides all necessary functionality to manage Caches and associated Services.

A Cache contains mappings of key to value, so-called entries. There are methods to create, access, update and delete these key-value pairs.

A UserManagedCache allows to actively define a specific cache handling in cases where the full functionality of CacheManager may not be necessary, for instance when the lifecycle of the cache is shorter than the application lifecycle.

For more information on these three classes refer to the following sections ...

... and the Java API docs of the Ehcache API on http://www.ehcache.org/documentation/.