Differences between CSOM and SSOM

The core differences between Client Side Object Model (CSOM) API and traditional Server Side Object Model(SSOM)

Further reading at http://intelliview.blogspot.co.uk/2014/10/sharepoint-2013-client-object-model.html

• Administration related task such as site back,service application management and workflow related tasks can be done only through Server Side object model. 

•  Site branding such as managing the master page,theme and CSS file cannot be done in Client Side object model. 

•  Request Batching (Series of Request for data retrieval on the Client context) submitted to the server in a single request.This can be done using Client side object model and REST API.