Zoom, Pan and Rotate
The model can be zoomed/panned in the model Viewports in various ways. The zoom and pan options are available in the toolbar, the Zoom sub-menu of the View menu, and through various keyboard and mouse shortcuts, as described below.
Zoom
The Zoom 
option zooms in or out of the original view area in the current Viewport. Select the icon from the current Viewport. Click and drag the mouse up to zoom in and down to zoom out. Without selecting the icon, you can also rotate the mouse wheel forwards to zoom in or backwards to zoom out.
Zoom Fit
The Zoom Fit option resets the model to its default size and location in the current Viewport. Select the icon
from the current Viewport or in the View menu. You can also hit the F2 key.
Zoom Window
The Zoom Window 
option allows you to zoom into any rectangular region of the current Viewport. Select the icon from the current Viewport. Click and drag the mouse to draw a zoom region. When you release the mouse the model view will be zoomed in to fit the drawn window size.
Pan
The Pan 
option allows you to move the model in any direction within the current Viewport. Select the icon from the Viewport and pan by clicking and dragging the mouse. You can also click and drag the mouse wheel while holding the CTRL key to pan.
Rotate
The Rotate 
option allows you to rotate the model within the current Viewport. Select the icon from the Viewport and rotate by clicking and dragging the mouse. You can also click and drag the mouse wheel to rotate.