A reflecting move is a move that can reflect flying projectiles.
Some reflectors just stay in place and reflect projectiles that hit it. Others don’t actually reflect; they simply absorb the projectile, often allowing you to send it back when you like.
Reflectors usually do not function against stationary and unlaunched projectiles. Sometimes, they are no good against super special moves.
The first reflecting move was Kisaragi Eiji’s Ryūeijin.
Also, World Heroes 2 had a pioneering projectile returning system (it was a special kind of preemptive block, akin to “Just Defense” in that one must block just before the projectile will hit).