The Services added while installing MS CRM 2013 and what are new from MS CRM 2011

Service	Description
Microsoft Dynamics CRM Asynchronous Processing Service	Services asynchronous processes such as bulk email and workflow.
Microsoft Dynamics CRM Asynchronous Processing Service (maintenance)	Services asynchronous maintenance such as encryption key generation for authentication and database deletion clean up.
Microsoft Dynamics CRM Unzip Service	Handles the uncompressing of zipped files for data import. This service is installed as part of the Web Application Server role.
Microsoft Dynamics CRM Sandbox Processing Service	The Sandbox Processing Service server role enables an isolated environment to allow for the execution of custom code, such as plug-ins.
Microsoft Dynamics CRM Monitoring Service (new)	Monitors all Microsoft Dynamics CRM Server 2013 server roles that are installed on the local computer.
Microsoft Dynamics CRM VSS Writer (new)	Provides an interface to backup and restore Dynamics CRM data by using the Windows Server Volume Shadow Copy Service (VSS) infrastructure.