Replication uses a number of standalone programs, called agents, to carry out the tasks associated with tracking changes and distributing data. By default, replication agents run as jobs scheduled under SQL Server Agent, and SQL Server Agent must be running for the jobs to run. Replication agents can also be run from the command line and by applications that use Replication Management Objects (RMO). Replication agents can be administered from SQL Server Replication Monitor and SQL Server Management Studio.
Snapshot Agent The Snapshot Agent is typically used with all types of replication. It prepares schema and initial data files of published tables and other objects, stores the snapshot files, and records information about synchronization in the distribution database. The Snapshot Agent runs at the Distributor.