Hard drives have traditionally been pretty dumb devices—for the most part, they neither know nor care about the machine they are attached to. For both internal and external drives, the setup is generally plain and simple: Plug your drive in, wait for the driver to install and—voilà!—more capacity.
A dumb drive is actually great if all you want is extra storage or a place to back up data from a single PC. But say you have multiple computers in the house, or a gaming system, or a networked security camera, or a huge music and movie collection that you’d like to stream out to a variety of portable devices. That’s when you want a hard drive with a brain—a network-attached storage (NAS) drive.
NAS drives aren’t hooked directly to any one computer. Instead, they connect to a router via Ethernet or Wi-Fi and are visible to any computer connected to that network. Because they are tied to the network, rather than to any one computer, NAS drives continue to be available even when your computers are turned off. They are, in fact, little computers in their own right, delivering most of the functionality of a business-style server with a more consumer-friendly interface and a more wallet-friendly price.