X10 has 2 standards that it uses (PLC and RF). In general, if a module is RF (310MHz radio frequency in the US), it will say so and will be compatible with all other X10 RF equipment (so long as it's US components). If it's not RF, it's going to be PLC (power line commands). In order to use the equipment, you must have a controlled module (lamp module, appliance module, light switch, etc) and a transmitter/remote control (key fob, palm pad, motion sensor, mini/maxi controller, etc). If the remote device is RF, you will need a transcoder to convert the RF signal to PLC (RR501, TM751, CM15A, etc).
The simplest configuration would probably be a lamp plugged into a lamp module (LM465) and plugged into the wall and a mini-controller (MC10A) plugged in at a different location. To turn on the light, you press the ON button for the unit code that the lamp module is set to.
TL;DR: X10 is RF and PLC. If it says RF it works with all RF. If it says PLC, it works with all PLC.