Which network-ready device facilitates file sharing and data backup?

So I found three network-ready devices that facilitate file sharing and data back up:

1. Home network server
2. Time Capsule
3. Network-attached storage

But what are those things, I hear you say? I'll try to explain them as well as I can:

Home network server

A home network server is a computer that functions as a server in a home network. As long as there's enough space on the hard drive and enough memory, a laptop or desktop computer can be used for this. Also the internet connection must be pretty good so it can handle multiple users accessing it. Anyone can log in to a PC on the network and access all the files shared with it. Sounds good!

Time Capsule

The Time Capsule is an Apple product, and is used with the Time Machine software. It's basically a wireless network device that works with Time Machine to backup data as well as share it with devices that connect to the Time Capsule.

Network-attached storage

I didn't know about this until I just searched it, and it sounds awesome. Network-attached storage, or NAS, is like an external hard drive that you plug into your laptop or desktop - but instead, it connects to your wireless router, so not only can you access the files stored on it, but so can everyone else connected to the network! This is how it works:

Hope this has helped. You might want to take a look at CNET's review of the latest Apple AirPort Time Capsule and Base Station: