Drawing axes are vital to understanding how Google SketchUp functions. The drawing axes in sketchUp are used to determine where you are (and where you want to go) in 3D space.
Axes help in creating modeling in SketchUp rapid, perfect, and comparatively intuitive.
In sketchup the global axis lines belong to the red, green and blue lines which are usually demonstrated in the drawing window. The point where these lines are intersected is known as the origin. The red line stands for the X-axis, green for the Y-axis and blue for the Z-axis. The Z-axis is the vertical one. Components obtain their own axes. The solid axis lines remain to the positive direction whereas the dotted axis lines remain on the negative side.