What is the difference between 2 cameras?

I just picked up a new (used) camera...
XC2CD2042WD-1

Looks like a 2CD2042WD-1

How does a XC2CD2042WD-1 differ from a 2CD2042WD-1. ???

I was able to upgrade firmware to latest/Last 2CD2042WD-1 firmware and it works ok.

Nosy as to what model differences are.

?????
Thanks for you help.