Match-on-action

Match on action is a technique used when continuity editors cut two shots so that the end of the first one looks exactly the same as the start of the second one (i.e they "match"). So if a man is walking into a room at the end of the first shot he and the door would have to be in the exact same position as at the start of the second shot. This ultimately is to make cuts invisible, or at least so smooth that the viewer doesn't take notice of the editing this allows for the audience to consecrate on the story instead of noticing the editing.