Input - Any machine that feeds data into a computer. For example, a keyboard is an input device, whereas a display monitor is an output device. Input devices other than the keyboard are sometimes called alternate input devices. Mice, trackballs, and light pensare all alternate input devices.

Output - Is any piece of computer hardware equipment used to communicate the results of data processing carried out by an information processing system (such as a computer) which converts the electronically generated information into human-readable form.

Touch screen - A display device that allows a user to interact with a computer by touching areas on the screen. most modern day phones are touch screen like the Iphone 6, the HTC one and the Samsung galaxy s 5.

Operating systems - The software that supports a computer's basic functions, such as scheduling tasks, executing applications, and controlling peripherals. the operating system help link up all the other systems like the mother board, the key board and the mouse and many more.