How to add a NAS device to your home network
A NAS (Network Attached Storage) device is an external hard drive that gets connected to your home network either through an ethernet cable or wirelessly using a wireless router. This device is accessable from any computer on your home network. Your are correct in thinking that you can just simply share out your hard drive on an existing computer, but in this situation, the computer must always be on and you also have to configure your desktop firewall so other users to access your computer and it must always be on.
I use a NAS device in my home network because it give me a common location to store all of my files. For example, I just recently purchased a new laptop with built in wireless and now when I am using the laptop, I can go to the NAS device to access my business files and also know that I am getting the most recent versions of the files and then even go to my desktop computer to access the same files.
Network Attached Storage devices are no longer just used by big companies for file storage. The common home network user can now purchase these for under $200.00 and use them for the whole family to store their common files.
We like wireless devices because of the flexability of not needing to run cables, but keep in mind that the wireless NAS devices are going to be slower.