SQL Server Agent
New Information - SQL Server 2000 SP3.
SQL Server Agent hosts and schedules the agents used in replication, and provides an easy way to run replication agents. When choosing to make a trusted connection, the replication agents run under the security context of the SQL Server Agent startup account. SQL Server Agent also controls and monitors several other operations outside of replication including monitoring the SQLServerAgent service, maintaining error logs, running jobs, and starting other processes.
Important In SQL Server 2000 Service Pack 3 and later, the SQL Server Agent proxy account must be configured with a login and password if a publication or subscription is created by a user who is not a member of the sysadmin fixed server role. For more information, see xp_sqlagent_proxy_account.