A gate or gateway is a point of entry to a space which is enclosed by walls. Gates may prevent or control the entry or exit of individuals, or they may be merely decorative. Other terms for gate include yett and port. The word is derived from old Norse "gat", meaning road or path, and originally referred to the gap in the wall or fence, rather than the barrier which closed it. The moving part or parts of a gateway may be considered "doors", as they are fixed at one side whilst opening and closing like one. A gate may have a latch that can be raised and lowered to both open a gate or prevent it from swinging. Locks are also used on gates to increase the security. Larger gates can be used for a whole building, such as a castle or fortified town. Actual doors can also be considered gates when they are used to block entry as prevalent within a gatehouse. Today, many gate doors are opened by an automated gate operator.