Trackball:

 Trackball:

                       A trackball can be used as an alternative to a mouse. This device has buttons similar to those on mouse. it has a large rotating on the ball. The position of the cursor on the screen is controlled by rotating the ball. 

                            An advantage of the trackball is that is it takes less space than mouse. Trackball is often includes in laptop computer. it can also be used as separated input device with desktop computer.

Touchpad / Trackpad:

                                              A touchpad is a small flat surface over which the user moves his finger. The movement of the finger moves in the cursor on the screen. A touchpad are commonly used with notebook computers. The user can also use an external wireless touchpad with desktop computer.

 

Pointing Stick:  

                               Pointing stick is a pressure-sensitive device. it is similar to a pencil eraser and exists between keys on the keyboard. it requires no additional space or cleaning like mouse. Pointing stick is normally used in notebook computer.

 

Touch Screen:

                              A touch screen is a touch-sensitive display device. the user can touch different parts of the screen with the finger or stylus to input data and issue commands. for example the user can use two finger to enlarge or rotated an image on the screen. 

                                 touch screen are commonly used in tables mobile device retail stored self-checkouts ATMs and information kiosks. Touch screen are popular because the user can interact with the computer easily without an external input device.

              Different types of touch screen are as follows:

Resistive :        

                    The touch screen that have resistive screen can sense pressure. it can used with a finger or an ordinary stylus. A resistive can also be used by someone wearing  gloves. They are only used in lower-end smartphone.

 

Capacitive :

                        The capacitive touch screen can sense the conductive properties of an object such as finger or specially designed stylus. Capacitive touch screens are much better and responsive to human touch than resistive touch screens. They are used is most of the higher-end smartphones.

                                Pen Input:

                           coming soon...............