A trackpad, also seen spelled track pad, is a user interface which interprets pressure and translates it into movement of a cursor. Laptops are commonly equipped with trackpads, and many drawing tablets and personal digital assistants (PDAs) use the same technology. While it can take some time to become accustomed to the trackpad interface, some computer users prefer using a trackpad to mousing. Many trackpads also offer additional programmable functions which can make them even more versatile.
The method through which a trackpad works is relatively simple. A trackpad has a network of transmitters and receivers which are capable of reading very subtle changes in electrical capacitance. A grounding object such as a finger dragged across the soft upper pad of the device alters the electrical current. The change is converted into a signal which the computer can read, resulting in a corresponding movement of the cursor on the screen.
Typically, a trackpad also includes mouse buttons which allow the user to click on and manipulate objects on screen. Many track pads also have a “tapping” function, in which the user can sharply tap on a trackpad to select an object or perform an operation which would normally require clicking. On operating systems which support a double clicking function, the user taps twice.
It is also possible to program specific tasks into different regions of the trackpad, such as scrolling. Tapping on a certain quadrant of a trackpad could also act to minimize windows, switch workspaces, or perform other frequent tasks, reducing the amount of effort required on the part of the user. Once a user becomes adept at using a trackpad, he or she can use it extremely rapidly and effectively.
Most trackpads are intelligently programmed so that they do not respond to inputs from things other than fingers. Many designers have the palm of the hand in mind when they design this functionality, since the palm often hovers over the trackpad on a laptop computer. This feature has been greatly refined since the 1980s, when trackpads were first introduced to the market. Other progress in the field has made trackpads much smoother and more pleasant to use, and has led to the development of drawing tablets and other offshoot technology.
An alternate name for a trackpad is “touchpad.” “Trackpad” is often used to refer specifically to such devices embedded in computers manufactured by Apple, while “touchpad” is used for similar devices in computers from other manufacturers. Technically, the terms are interchangeable, although Apple devotees may not appreciate it.