Which is the 3 mouse button?

The third mouse button on a computer mouse is typically the middle button, which is usually integrated into the scroll wheel. On a standard three-button mouse, you have left button as button one, right button as button two, and the middle button as button three. You can press the scroll wheel down like a button to activate it, and this is called middle-clicking. Middle-click has many useful functions, for example in a web browser middle-clicking a link opens it in a new tab, middle-clicking a tab closes it, and in many design programs middle-click is used for panning or rotating the view. On some mice, especially gaming mice or office productivity mice like the Logitech MX Master series, the third button might be a separate button near the scroll wheel or a side button, but by standard Windows and Mac definitions, button three is the middle click. You can customize what button three does in your mouse settings or with software like Logitech Options or Razer Synapse. If your mouse only has two buttons and no clickable wheel, you may not have a third button, but almost all modern mice do include it as part of the scroll wheel.