This is correct. You can use any type of projector, and usually any type of thin white screen (preferably made out of stretched fabric) will do. The issue is usually not equipment, but space. You need enough room between your projector & your screen (ie, room backstage) to make a decent-sized image. Your projector should come with specs/photometrics to be able to figure out how far it needs to be from the screen to get whatever sized image you need/want. I find you use almost as much room backstage (between the projector & the screen) as you use for the rest of your set onstage...so just keep that in mind!