The information that a computer produces is called output. In the computer, output is in the form of a binary code. Output hardware, such as monitors and printers, decodes the binary code and puts it in the form you can understand. Output can be display on the screen or printed on paper. Printed output is called a hard copy. Output on screen is called a soft copy.

   A monitor displays computer data on the screen. The characters and pictures that we see on the screen are made up of dots, also called picture elements (pixels). The total number of pixels in which the display is divided both horizontally and vertically is known as the resolution. Typical resolutions are 1366*768, 1600*900 or 1920*1080 pixels.

Nowadays flat screen monitors are fashionable. Many of these use liquid crystal display (LCD) screens. An LCD screen is filled with molecules (tiny particles) of liquid which reflects light. When the screen is scanned by the computer, some molecules block light in different amounts, so some pixels turn dark and form part of the image.

A few computers still have cathode ray monitors. They work similar to TV sets. Electrical signals are converted into an image on the screen by a device called a cathode ray tube (CRT). A CRT contains a gun that fires a beam of electrons (electrical particles) at the screen.

   Using a sound synthesizer, computers can produce output in the form of sound. Some sound software can create waves that are similar to those of human speech. This is called speech synthesis. Some telephone enquiry services use speech synthesis.