An element is an atomic entry in a cache. It has a key, a value, and a record of accesses. Elements are put into and removed from caches. They can also expire and be removed by the cache, depending on the cache settings.

There is an API for Objects in addition to the one for Serializable. Non-serializable Objects can be stored only in heap. If an attempt is made to persist them, they are discarded with a DEBUG-level log message but no error.

The APIs are identical except for the return methods from Element: getKeyValue() and getObjectValue() are used by the Object API in place of getKey() and getValue().