A Hard Drive is a type of data storage device which is used for storing and retrieving digital information.
Optical Drive is a device used for producing or controlling light.
Input and Output Devices
Input devices are devices that can be used to insert data in to your computer.Output devices are devices connected to a computer and used to transfer data out of the computer in the form of text, images, sounds, or other media.
A touch screen is a display device which allows the user to interact with a device by touching areas on the screen.