Music Match and downloads

I have Music Match and Apple Music. I also have thousands of cd’s that I’ve ripped into iTunes. I listen at home, at office, in the car through my iPhone. My question is because I really don’t understand exactly what I have. If I delete downloads to save memory on my computer, is the music still available to me or do I need to keep the downloads on the computer so I can have musicmatch deliver them on my other devices? Obviously I’m confused.

thanks.