Please explain the GB on iphone to me?

I just got 1 gb instead of unlimited data, but when I go to storage it says 2.4 GB used. Is this the same GB as the gbs I'm paying for to search the web and other stuff? Did I go over my 1 GB in just 2 days? Also, how would I know if I used up all the 1 Gb, will the phone stop working? Please explain to me like I'm a retarded 5 year old. I just don't understand. I have 20 pics and 101 songs and 12 apps. Is this too much? In the about section it says capacity 13.2 GB and Available 10.8 GB what is this?

Data and storage are completely different. Data is basically mobile Wi-Fi, and that's a terrible way of explaining it. You know 3G? That's data. Data is bought in chunks. It can be anywhere from 1 GB to unlimited. Each month, your data resets.

The 1GB of data is how much you can use a month.
The 2.4GB of storage is how much you have used in terms of holding things on the iPhone itself, like media, apps, etc.

If you go over or come close you may get a text stating that. No the phone wouldn't stop working.