Liferay leverages OSCache for caching up until 4.3.0. Starting with Liferay 4.3.1, OSCache has been replaced by EhCache. See Caching (EhCache)

Look at the classes listed and you should be able to see a pattern.

Some properties files to know about

 **cache-single-vm.properties** - This is a single cache 
 **cache-multi-vm.properties** - This is a cache for a cluster

Look at these classes used for a cluster using the ClusterPool class

 CalEventLocalUtil
 CMSServletUtil
 JournalContentUtil
 LayoutCacheUtil
 PortletPreferencesLocalUtil
 AlfrescoContentCacheUtil

Look at these classes used for a single cache

 LastModifiedCSS
 LastModifiedJavaScript