I have a sustain pedal for my keyboard. My references are talking about compressor pedals, otherwise known as sustainer pedals?
Is the sustainer pedal just the same as a sustain pedal but used for guitars, or as just a more advanced alternative for both a guitar and a keyboard?
No. A sustain pedal is a simple switch with a piece of cable attached that the keyboard uses to emulate the function of the sustain pedal on the piano - which basically means "let ring the notes when the pedal is depressed even if you lift your fingers off the keys".
A sustainer pedal is a compressor, which is a thing that that limits the dynamic range of the audio signal - it's a caps lock for audio. Loud is loud and soft is loud as well.
