The Camera view displays a three dimensional rendering of the model wholly contained in the Working-Volume.
To view the model from different angles, hold down the left mouse button (the cursor turns into a hand when over the camera view) over the camera view and move the mouse to the desired view.
For faster, more interactive viewing, temporarily toggle the camera view to Wireframe, choose the desired view, and then toggle back to OpenGL shading.
The Camera View defaults to using OpenGL shading. You can quicky toggle between the shaded OpenGL Shaded Camera view and the Wireframe Camera view by pressing F11 or right clicking on the Camera window and choosing "Hide/Show OpenGL Camera View".
See also:
Hidden Line Camera View
Quick Render Preview