Tiling technique

Hi,

i was wandering why Iso and Rectangle based Tiling technique?
rectangle tiling can also represent the Iso tile based map, isn't it?

I would like to know why is it 2 different way of this.

The usual reason for the difference is simply for perspective.However, there is nothing to stop you putting iso images on a rectangular/square tile map although you may need a seperate 'walkability' map (which isn't always a bad thing).