You should be familiar with how the mouse buttons are used.
The left mouse button is used to perform activities such as placing the cursor in text fields, selecting objects in the Display window, selecting menu commands, and so on.
The middle mouse button is used to pan the display using a press and drag action. When in pan mode, the cursor changes to a “pan cursor”. If your mouse has a scrolling wheel, you may also use this to zoom in (scroll forward) and out (scroll reverse) of the view.
The right mouse button displays context-sensitive pop-up menus in various windows, such as the Display, Layers, Project and Selection windows.