ALL YOU NEED TO KNOW ABOUT COMPUTERS
some common optical devices include cd, dvd, blu-ray and ext. CD and DVD writers, such as CD-R and DVD-R drives use a laser to both read and write data on the discs. The laser used for writing the data is much more powerful than the laser that reads the data, as it "burns" the bumps and dips into the disc.
An input device is any device that provides input to a computer. there are dozens of possible input devices, but the most two common ones are a keyboard and a mouse. Every you press on the keyboard and every movement or click you make with the mouse send a specific input signal to the computer. the command allow you to open programs, type messages, drag objects, and perform many other functions on your computer.
Any device that outputs information from the computer is called an output device. Since most information from a computer is output in either a visual or auditory format, The most common output devices are a monitor and speakers. These to devices provide instance feedback to the users input, such as displaying characters as they are typed or playing a song selected from a play list.
A touch screen is a display that also serves as an input device. Some touchscreen devices need an proprietary pen. The modern touchscreen detect human touch. Since touchscreen devices accept input directly through the screen, they do not external devices, such as mouse and keyboards. This makes touchscreens ideal for computers kiosks, as well as portable devices, such as tablets and smartphones.