The All New Ipad 4
The Ipad was a touch screen device that was released on the 3rd of April 2010. The first Ipads did not have siri, cameras or many other advantages that modern day Ipads have. The 2nd Ipad was the Ipad 2 it had a camera and siri, retina display was not provided with the standard model. Today the 4th generation Ipad has large blaring speakers siri and a camera. The 3rd generation Ipad was not really a model but more of a beta (test version) of the 4th generation Ipad... so not many people bought the Ipad 3.
Ipad mini
The Ipad mini was a later version of the Ipad it was halfway between an iPod touch and and Ipad. It had the same amount of pixels as the normal Ipad giving it a higher resolution than the Ipads'. Its characteristics are much the same as the Ipad which is why it is classified and Ipad mini not a Ipod large. The Ipad minis' are more like children's Ipad but adults still acquire the Ipad mini.