This topic assumes you have read Deployment architecture.
The work needed to install and configure a broker is minimal: the administrator needs to configure the broker and configure the users to access the Helix Server through the broker. Broker configuration involves the use of a configuration file that contains rules for specifying which commands individual users can execute and how commands are to be redirected to the appropriate Perforce service. You do not need to back up the broker. In case of failure, you just need to restart it and make sure that its configuration file has not been corrupted.
From the perspective of the end user, the broker is transparent: users connect to a Helix Broker just as they would connect to any other Helix Core Server.
Historically, brokers were the only means to offload 'read only' traffic from a master server to a replica. We now recommend using forwarding-replica or forwarding-standby servers for such offloading because they handle it automatically.