The Macintosh popularized many modern computer techniques such as mouse usage, and the windows and icons desktop metaphor. But one major interface innovation reached the public on Windows: right-clicking with a two-button mouse to bring up a contextual menu. MacBooks have one button under the trackpad, or a clickable trackpad, so there are alternative methods of right-clicking.
How to Right-Click
The standard method of right-clicking in Mac OS X, which works on any MacBook, is the control-click: hold down the control key near the far left of the bottom row of the keyboard when clicking the trackpad button. An alternative method is to hold two fingers on the trackpad while clicking the button, but this does not work on the original MacBook models. MacBooks released in 2010 and later allow you to specify a portion of the trackpad that acts as a right-click. You can also use a USB two-button mouse, which provides a standard left button as well as a right-click button.
A contextual menu is a menu of commands that changes depending upon where you click the mouse. For example, if you right-click on a folder on your Desktop, you are provided choices including compression of the folder, creating an alias to it, or moving it to the trash. However, if you right-click on the Desktop background, your options include changing the background picture, cleaning up all Desktop icons, and creating a new folder.
One-Button Vs. Multi-Button
Macintoshes have historically been famous for their use of single-button pointing devices, when other computers shipped with mice that have two buttons. This was an early design choice. The first computer to use a mouse at Xerox PARC had three buttons, with different commands issued by left-clicking, middle-clicking and right-clicking. Apple engineers did research to show that a single button was more efficient than a multi-button setup, and stuck with the choice while two-button mice became the norm.
Users with disabilities, or people who wish to operate their Macs with one hand, can use the Universal Access preference pane to assist them. Click on the "Keyboard" tab and click the checkbox next to "Press the Shift key five times to turn Sticky Keys on or off." When you press shift five times, the next modifier key, including the control key, will "stick" until you hit the next key or button. This allows you to right-click without holding down the control key.