First of all - you are wondering what a Time Capsule is. It is a computer device made by Apple Computers.
It is a small silent 8 x 8 x 1 inch box. It provides two services. First - it is a wireless router that sends wifi Internet signals from you cable modem to any computer within shouting distance. Second - it automatically backs up your computer hard drive wirelessly.
One of the dirty little secrets of owning a computer is that your hard drive is going to fail. It is one of the few moving parts in a computer and it fails from wear and tear. You are supposed to back up your data from time to time - but most users get a little to confident and lazy. They think their hard drive will never fail. The Time Capsule automatically backs up your data - hourly - and daily. It uses a program called Time Machine to store your data. With Time Machine you can go back to any date - and see your computer files on that date. It is like magic - going back in time - thus the name.
I have been using my Time Capsule for two years. It has been silently backing up my computer and Lulu's too. It can back up several computers at once - until its 500 GB hard drive is full - then it dumps older copies of your data.
Anyway - the other day my Time Capsule failed. It refused to power up. I called Apple - told them about the problem. After checking on the Internet I also noticed this was a known problem. Apple said they would send a brand new Time Capsule to me in overnight mail for free. They asked that I put the old one in the return box - and they would pay the postage to return it. The next morning at 10 AM - the new Time Capsule arrived. I had it up and running in minutes.
The new one has a couple of new settings that are nice. First - it allows you to use N speed wifi and G speed wifi devices at the same time without slowing of service. My iPhone is G speed and my MacBook is N speed. Second - it allows you to set up a "guest" network to limit what a guest user can see. In the past I used to leave my wifi network open to anyone that wanted to use it - but recently I locked it with a password - because I think it was slowing down due to other users.
The Time Capsule cost about $300. At least if yours fails two years later - Apple will send a new one for free.