IntelliMouse
Alternatively referred to as a wheel mouse or a scroll mouse, the IntelliMouse is a mouse developed by Microsoft in 1996 that has a wheel between the left and right mouse buttons that enables the user to easily scroll up and down using the wheel instead of having to use the vertical scroll bar. In addition to being able to scroll, these mice also have the ability to use the wheel as a button by pressing down on the wheel. An example of how this button could be used is users who are using Mozilla Firefox can use the middle-button (wheel) to open a link in a tab.
In the image to the right, is an example of what the Microsoft IntelliMouse looks like.Because of the wide popularity and great functionality of this wheel, this mouse has become a standard mouse used with all new computers. Although "IntelliMouse" is a Microsoft Trademark, these mice are developed by numerous different companies today. Another popular manufacturer of these mice is Logitech.
Also see: Mouse definitions