A catch occurs when a forward pass is completed (by the offense) or intercepted (by the defense) and a player who is inbounds...

a) secures control of the ball in his hands or arms prior to the ball touching the ground and;

b) touches the ground inbounds with both feet or with any part of his body other than his hands and;

c) after (a) and (b) have been fulfilled, performs any act common to the game (e.g., tuck the ball away, extend it forward, take an additional step, turn upfield, or avoid or ward off an opponent), or he maintains control of the ball long enough to do so.