One Point Perspective
The illusion of space is achieved through perspective drawing techniques and shading.

Perspective, is basically things getting smaller the further they are
away from you

One Point perspective
Perspective in which all the parallel lines converge at one single point on the horizon line.

Vanishing Point
The point where parallel lines appear to meet in the distance.  

Horizon Line
The horizontal line that defines the edge between the earth and the sky.