Mouse A mouse is computer hardware used for navigation through files displayed on the computer screen. The standard mouse has two buttons and a scroll ball. The two buttons are used to select actions on the screen by clicking on either of the buttons for different functions. Most computer user interfaces allow users to customise the functions of the two buttons on the mouse. One of the advantages of using a mouse is its ability to simplify navigation through files and folders on a computer by simply pointing and clicking. The main disadvantage and limitation of using a mouse is its space requirement. A mouse cannot be used in an area without ample physical space to drag and scroll (El Kaliouby & Robinson, 2003). Foot mouse A foot mouse is a specialised type of a mouse that is operated by the feet. Users with disabilities mainly use the foot mouse. The design of a foot mouse depicts a footpad with several buttons that serve different purposes. The footpad also has a navigation ball that is rolled to the foot to move the cursor on a computer screen. There is also afoot mouse for computer experts who prefer using their feet to free their hands for higher performance in different activities on their computers. The advantage of using a foot mouse is that it enables the disabled people to enjoy the easier navigation on their computers. Its disadvantage is that it takes a lot of time for the user to master the manipulation of a foot mouse. Its main limitation is its requirement for larger working spaces because it is larger than a normal mouse ((El Kaliouby & Robinson, 2003). Joystick Joysticks are input devices used to control characters in computer games. A joystick comprises of a control column that is attached to a base that allows easy rotation of the stick. The stick normally has other support buttons used for different purposes like executing moves in the game. Joysticks work under the principle of motion whereby the characters on the screen move in a similar manner as the motion executed by the user on the joystick. The advantage of using a joystick is that it acts as a central control centre for gaming users. The buttons are attached to a stick, making it easy for the user to execute moves easily. The disadvantage of using a joystick that becomes tiring because the user has to keep moving his or her hand. Its limit is the availability of working space (El Kaliouby & Robinson, 2003). Trackball A trackball operates like a mouse. The standard trackball is made of a socket with a rolling ball and several buttons. The trackball looks like an inverted mouse, and it is very easy to navigate using the device. A trackball user utilises his palm and fingers to get through files on a computer screen. A person using a computer rolls the ball, and the cursor on the screen move to the required place while clicking on the buttons where required. The main advantage of using a trackball over a mouse is its ability to eliminate the large working space requirement. A trackball operates on a static point; hence, it does not require large working spaces. Its disadvantage is it requires more accuracy and expertise in navigation because a slight touch on the ball moves the cursor (El Kaliouby & Robinson, 2003). Touch sc