A climbing hold is a shaped grip that is usually attached to a climbing wall so climbers can grab or step on it. Climbing holds come in a large array of sizes and shapes to provide different levels of challenge to a climber.
Volumes are an extremely large type of hold that any variety of holds can be attached to. The volume is attached to the wall, and it has pre-placed t-nuts in it to which other holds can be attached. Volumes are made of GRP materials.