The option specifies where certain jobs are delegated. You can run jobs on devices on a specific managed media server or on the devices that are on a group of managed media servers. This option only displays if you have the Central Admin Server Option installed.
For example, you can run Exchange database backups only on the devices that are attached to managed media servers in a pool named Exchange Backups. You would select this option and then select the Exchange Backups media server pool.