Yes a remote control signal can be coded with analog pulses or digital codes. An example of an analog remote control scheme might be DTMF tones. These are the same audio frequencies used in touchtone phones. Or, on the other hand, a digital scheme might be employed using, for instance, a 7 bit stream with stop and start bits to synchronize the transmission.
This would be necessary if the same frequency is being used for all the remotes.
In an IR remote scheme you might modulate the signal digitally, or you might be able to simply use band pass filtering to respond to a particular IR frequency.