Isometric View
With an isometric view, the object's angles are distorted in order to show all three dimensions of the object. Right angles become more or less than 90°, squares become parallelograms, etc.
Orthographic Views
The main advantage of using orthographic views over an isometric view is that you are able to see the true shape of an object without any distortion; right angles will be 90° and squares will be squares.