Isometric drawing is using the thing you are drawing's exact length and size to draw the picture of it.Image URL:iso3.gif
Perspective drawing is drawing from your perspective, with a vanishing point where parallel lines end at, and figures further away would be muchsmaller.
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An oblique drawing is a 3 dimensional image of an object, with width as a horizontal line, but depth drawn back at any angle.
An orthographic drawing is a drawing with only a view of one of the object's sides shown, such as house plans.