The central processing unit is the brains of the computer. The CPU processes the input from keyboards, mouse, and digital cameras into output. There are 4 kinds of output. They are the following: text, graphics, video. and sound The output devices in which the information is displayed can be the monitor or printer. Computers process information in electrical pulses. Each electrical pulse contains an instruction received from random access memory. The clock speed of a CPU is measured in mega hertz or gigahertz. This means that a computer can process millions or billions of instructions per second. The instructions are carried to the CPU from RAM through electrical impulses.