Purpose of "Registering" a device with C4

[TexasUser]

I'm very new to C4.  My Onkyo AVR (TX-RZ820) says the following in the manual:

"Control4: Register this unit if you are using a Control4 system. "

I asked my dealer and he said, "We did not register the Onkyo with control4, it is brought into the project with it’s unique UUID so I am unclear for the need ."

I'm interested in what "registering" the AVR with C4 does, or is it just a different way of saying what my dealer did?

Thanks!

[sonic30101]

Onkyo manual should say identify not register. Your dealer did it correctly