Which Ipad is newer?

I was looking through various Ipads for my grandmother, and I was wondering which was newer? An Ipad fourth generation, or the Ipad 2? Yes, yes, I know, it sounds like a silly question, but hear me out. I was thinking that the Ipad 2 was newer, the order going like this.

Ipad 1st generation
Ipad 2nd generation
Ipad 3rd generation
Ipad 4th generation
Ipad 2 1st generation

Then it occurred to me that the "2" might also mean generation. So the Ipad 2 would basically be the second item in the above list. Is this how it is, or is my first guess correct?

Here in Brazil they still sell iPad 1 as if they were the newest thing. In the official iStores!