Cache functionality, including remote synchronization, is part of the EPiServer framework available for all EPiServer products. To allow cache management to be effectively shared between for instance CMS and Commerce. There are two interfaces, IObjectInstanceCache and ISynchronizedObjectInstanceCache, that can be used to access this functionality. Changes made using the ISynchronizedObjectInstanceCache interface are synchronized between servers using events in load balanced environments.
The recommendation is to take a dependency on ISynchronizedObjectInstanceCache instead if you previously were using the CacheManager class in CMS, the new interface provides the same functionality. The IObjectInstanceCache is intended to directly supersede IRuntimeCache previously only used by CMS, the new interface has been rewritten to support different cache implementations by abstracting the CacheDependency class among other things. The underlying default implementation of IObjectInstanceCache still rely on HttpRuntime.Cache.