Match-on-Action

Match-on-Action is an editing technique in which one shot cuts into another shot portraying the action of the first shot also in the second. (Confusing?) 

For example, when someone opens a door and the first shot is looking at the person's hand opening the door, and then it goes to the second shot to a view from inside the room looking at the door open. (Still confused? Just look at the amazingly drawn picture). 
This technique is to show to show a continuity in the scene and to create a 'visual bridge' which is supposed to take viewers' attention away from from slight editing issues or cutting problems.