|Apc||Alternative PHP Cache or APC / APCu|
Abstract cache class, implementing the Cache_Method_Interface interface. Used to provide common methods and properties to the caching classes
Filebased caching is the fallback if nothing else is available, it simply uses the filesystem to store queries results in order to try to reduce the number of queries per time period.
|Memcache||Memcached and Memcache.|
|Zend||Zend caching engine.|
In order to work with ElkArte any caching method must implement this interface