There is the technical drawing for a number of different types of spatial view. They are drawing objects (components, assemblies, etc.) in a three-dimensional representation drawn. The spatial representation of objects should facilitate the technical drawing to understand, since the true form of components from the perspective easier and quicker to recognize.
The spatial views are drawing the technical effects drawn without perspective. This means that the body edges, the parallel and always parallel drawn - as opposed to artistic drawings, which often escape with points are used to perspectival effects. For all those dei more about perspective drawing want to learn, this manual on art course-online.de interesting: Perspective Drawing
What you should note, however, is that in certain views the body edges, which lost to the rear, on a scale of 1:2 shortened drawn. You learn more in the following descriptions.
When technical drawing unterscheided the isometric Axonometric, the Front Axonometric, the Planometrische projection and the Cabinet projection. The views differ in the angle in which to rear ongoing component edges and on a scale in which they are drawn.
As the different views and how they are defined, you can see in the images below.
The Isometric axonometric is a view in which the component edges (which in reality in the 90 degree angle to each other) at a 30 degree angle to the horizontal line drawn. It is none of the edges verküzt drawn.

isometrische Axonometrie
Angle 30°/30°
Aspect Ratio 1:1
In the Front Axonometric, a component edge in a 7 ° angle to the horizon, the other edge in a 42 ° angle. Components in the Front View sketching is especially useful when a certain side of the component is particularly important. This page then that should be in the 7 ° angle to the horizontal stands.
The component edge in the 42 ° angle is shown, is in the aspect ratio of 1:2 draw - that is half as long as in reality.

dimetrische Axonometrie
Angle 7°/42°
Aspect Ratio 1:2
The Planometrische projection is a ungenormte view. They are both part edges at a 45 degree angle to the horizontal line drawn. The aspect ratio in this technical view is 1:1 - as in the isometric view.

Planometrische-Projection
Angle 45°/45°
Aspect Ratio 1:1
The Cabinet-projection is just as the Planometrische tree A ungenormte view. At the Cabinet-view we have a component edge displayed horizontally, the second edge (in reality in the 90 degree angle to other stands) in the 45 ° drawn. That edge is just as well in the Front view in the aspect ratio of 1:2 draw.

Kabinett-Projection
Angle 0°/45°
Aspect Ratio 1:2