In X10 there is only one type normally seen.
One that takes the X10 Power Line Signal on
the one phase of a houses wiring and repeats
it back on the other phase. To help with
weak signals found frequently on the other
phase.
I believe that X10 also has a remote
extender that sends the RF signal from a
remote to a tranceiver that maybe on the
fringe of receiving the signals.
Repeaters for the 2.4Ghz camera signals as
far as I have seen don't exsist as the
transmitter would have to send the received
signal back on a different frequency to not
interfere with itself.