You can find degtailed information on each of them in the "NetBackup Commands" admin guides. You can find most all of the NetBackup manuals and documentation on the installation CDs. You can also download them from:
http://www.symantec.com/business/support/overview.jsp?pid=15143
Here is the info from the nbrb
nbrb (1M)
NAME
nbrb
- run NetBackup Resource Broker
SYNOPSIS
/usr/openv/netbackup/bin/nbrb [-console] [-terminate]
DESCRIPTION
The NetBackup Resource Broker binary (
NetBackup starts and remains active. This service makes the allocations for
such things as storage units, tape drives, and client reservations. This service
works closely with the EMM to obtain physical and logical the resources that a
job requires to run. Physical resources can be storage units, tape drives, and
media IDs. Logical resources can be named resources, max jobs per client, max
jobs per policy, and multiplexed groups as resources that
nbrb) is a service that starts whennbjm uses.
OPTIONS
-console
Enables you to start NetBackup in console mode.
-terminate
Enables you to stop the
nbrb.
SEE ALSO
nbjm(1M)
, nbpem(1M)