Hi and welcome.
Resolume is a real time video playback and video source generative software. It is a stand alone application.
So think of it as more of a mix between After Effects and Premiere Pro (to roughly describe it).
Let's say you have a clip of some slow moving clouds in Premiere Pro and you want to make them move faster. In Premiere Pro you would do speed adjust, In Resolume you would do the same, but with added features such as speed controlled by BPM if you wanted, or even the playhead synced to a linear time code file.
Let's say you want to make your clouds red and then turn them into a kaleidoscope, you can do that as well in Resolume by just dragging in FX on top of your clip. Everything renders in real time, so its for live playback and doesn't require several minutes (or hours) of rendering like you would see in After Effects.
You can also generate visuals from within the program such as creating lines or circles then animating them to a playhead or bpm. then applying FX on top of them.
Resolume is not however a timeline based program so there is no keyframing. there are other external application that can sync up with Resolume that can potentially make it a timeline based program if you want to spend the time setting them all up.
The demo is free and has all the features. Give it a test spin and see what you think. ALSO.... The training is now free. WELL worth the time to go through it all.
In regards to audio, Yes you can do audio as well, but the files should be .wav and not .mp3