NAS may refer to any of the following:
1. Short for Network Access Server, NAS is also known as a terminal server and is a computer or network device that communicates you with another computer or service. For example, when you dial in to connect to the Internet, you're dialing into a NAS.
2. Short for Network-Attached Storage, NAS is any type of storage device that is connected to a network and provides a network with additional storage. A NAS does not have any processing power on its own, meaning it cannot be used to execute or run network shared programs.