Section View

This short entry shows a simple utility for viewing your mesh, which is the section view (or cutaway view).  To enable this view enter [ALT + B].  This produces an action similar to the box select [CTRL + B], except, what you select will maintain in the view, and everything else will be hidden.

In this example, I selected the right half of suzanne from the top view.

You'll notice that when viewing the mesh from the side, you can now see inside since the left side is hidden.  The section view can be turned off by pressing [ALT + B] again.