What is a NAS (Network Attached Storage Device)?

Network Attached Storage devices connect to a network; they function as a typical hard drive, but service every authenticated device on the local network. Most NAS units ship with several drives to support various RAID configurations and an on-board operating system with a firewall to facilitate remote-network operations.

The popularity of NAS units has increased in conjunction with the growth of large personal digital-media libraries. More enthusiasts stream media over home networks to network media players/Media Streamers, Smart TVs, network Blu-ray Disc players, and to other computers.

The NAS acts as a media server, facilitating media access to network-connected computers and compatible playback devices. Because it's a server, compatible playback devices access files directly. Many NAS units are optionally accessible through a web browser when you are away from home; view photos and movies and listen to the music saved on the NAS by logging into your manufacturer's portal. 

Some NAS units require loading software onto your computer. The software may be needed for your computer to connect to the NAS, and often makes it easier to upload files from your computer to the NAS. Most software includes a feature that automatically backs up your computer or specific files to the NAS device. 

However, most NAS devices support local sharing through standard protocols like Samba, so even without the special software, Windows, Mac, and Linux computers should connect normally.

The value of a NAS shines brightest when several different computers connect to the same, protected, local area network:

• You don’t have to leave your computer turned on for compatible playback devices to access your movies, photos or music. 
• Add to your media library without using storage space on your computer’s hard drive—a 1 TB drive can store up to 120 movies, 250,000 songs or 200,000 photos or any combination of files. 
• Save photos, video, and still image files from all the computers to one central storage place. 
• Access the files from everyone in your household that saves to the NAS (if they give you permission) even if they have left home with their laptop. 
• Many NAS devices allow remote access to media files. When away from home you can play your stored media on any device that has an internet browser—laptop, tablet, or smartphone. 
• A NAS device that is a DLNA certified “media server” connects easily to other DLNA certified playback devices.
• Back up your computer to the NAS, or back up your important files in case your computer fails—manually or automatically.

NAS drives, because they're exposed to the network, offer some additional risk, however:

• NAS devices cost more than an external hard drive with the same amount of storage.
• Older NAS devices may have problems connecting to computers and may not be DLNA certified. They may not be visible to some Network media players/streamers, SmartTV's, or Networked Blu-ray Disc players.
• Misconfigured security on a NAS device may expose some data to the entire LAN or even to the internet.