There are different styles of monitors. One of these is the one already shown. It is called a CRT monitor. It takes more power than the other popular kind, called LCDs (see Figure 1.3). However, CRT monitors work faster, which makes them better for fast games because the movement will blur less. LCDs are thinner than CRTs, but they are more expensive.

Monitors are only one way the computer can output information for you to see. Another popular output device is called a printer (see Figure 1.4). Printers are used to put data on paper. This is called hard copy, what monitors show is called soft copy. Computers can also output sounds; this is also soft copy. 

        
There are also different kinds of input hardware. The two most important of which are the mouse and the keyboard. A mouse looks like Figure 1.5 it is used to move the cursor around the screen (monitor display). A keyboard (see Figure 1.6) is used to enter (type) letters, numbers, and other symbols into a computer.

Computers store all data in binary code, which is a number system that only uses ones and zeros. One digit in binary code is called a bit, eight bits is called a byte. A byte is the amount of space one letter takes up. However when letters are formatted specially they get bigger, and so usually things on a computer are thousands of bytes in size.