I'm learning how to program software synthesizer. I came across with these two types of patch described as "pad" and "drone". They sound somewhat similar for me.
Could someone explain what the difference is between those two?
On a synth, they're pretty much the same thing, depending on how you play it.
They're both relatively constant, maintaining a sound bed underneath your melodic & rhythmic structure. They don't have any kind of 'spiky' or rhythmic essence to them - slow, drifting, would best describe them.
Essentially, though, a drone never changes note[s] - like the drones on bagpipes or hurdy-gurdy etc - so you have to really play in a single key.
A pad is 'drone-like' but free to follow your chord progression.