Isometric drawings are also easier to scale from plain view.
Oblique drawings show a 3-dimensional view of an object, the difference from isometric drawing is: oblique drawings show you what is in between the objects. Take a look at this diagram, taken from Thinkquest.org's Library (information also abstracted from that site) to see the different steps to draw an oblique drawing:
Firstly, draw a tic-tac-toe-like diagram. That will be your diagram's backbone. Second, make your 'backbone' three-dimensional by making it look like a cube with lines inside it. Third, draw the thing in which you want to draw (let's say, a smaller cube, or a stair-like shape) and outline it, then erase the original cube, and, lastly, add the measurements.
One more thing about oblique drawing: calivier, normal and cabinet obliques.
Calivier Oblique = Full measurement used in drawing (which means, if you want to draw the stairs, you need a very big piece of paper)
Normal Oblique = Depth 3/4 of real measurement
Cabinet Oblique = Depth half of real measurement
Related to isometric drawings. Orthographic drawings are of those done by designers. From all views top, bottom, side to side. This is an example of a 'rough' orthographic drawing:
This 'box' if so called cut, it would look like this:
As you can see, there are six sides: front, top, rear, bottom, left-side and right-side view.
And now, the 'box' is made into a car, and it comes out like this:
That is why I said it was like a designer's drawing, cause we look from every side of the object: to get the feeling of 3-D out.
With help from http://www.cdli.ca/depted/g7/ortho.htm
That concludes my explanation and comparing of all the different types of drawings listed.