By default OutputCacheLocation.Server
simply means that the data is stored in IIS Worker Process
memory space. if you enabled Kernel-Mode
caching the data is stored in the Http.Sys
driver memory space (which is an Operating System process, not IIS process).
In the case of Windows Azure Shared Caching
, the data is serialized and stored in a special process on the Virtual Machine instance, that process is then responsible for managing and synchronization of the cached data between all of the Role instances.