I genuinely had no idea that a license wasn't required to fly a glider (or "ultralight" based on my reading). I'd imagine there is very high overlap anyway -- most glider pilots being pilots, etc.
Weirdly often not! They’re quite different recreational activities.
Flying powered is a “go to the airfield and takeoff” whereas gliding is more of an all-day team sport at most clubs as there’s a lot of ground handling required for towing, winches etc.
Yes, a private pilot's license (PPL glider) is required to fly gliders. OP probably meant that they were considering adding a rating for powered airplanes (PPL ASEL - airplane, single-engine, land).
Alternatively perhaps they mean that they took some lessons in a glider as a student pilot and considered going further and getting the license.
Same in the US. "Airplane single-engine land" and "glider" are two possible private pilot ratings (others include rotorcraft, balloon, multi-engine, seaplane, etc).
Flying powered is a “go to the airfield and takeoff” whereas gliding is more of an all-day team sport at most clubs as there’s a lot of ground handling required for towing, winches etc.