What is backup?
Backup is making additional copies of data, in the case the original copy becomes inaccessible. In other words: Make a safety copy of your documents and pictures, so they will not disappear when your computer crashes.
There are two kinds of people in the world: Those who have lost data and those who will loose data. You better have another copy when you loose yours.
Usually it is harddrives that break, but it can also happen due to computer virus, errors in programs, theft, water damage, fire, natural disasters and in many other ways.
Just make another copy of the data. That's it!
Well, depending on how you do that, you will get a cheap or expensive solution, which might be easy or hard to use and which may protect you just a little or very well. This blog is basically about those 3 paramters: Price, ease of use and protection.