5. Computer Hardware. Computer hardware refers to the physical parts of a computer that you
can see and touch. Each computer can be broken down into four principle hardware
components: Input devices (keyboard, mouse, scanner, modem), central processing unit (also
known as the system unit; it houses the circuitry and disk drives), output devices (CRT or
monitor, printer, speakers, modem), and memory (ROM and RAM chips). Below is an
illustration of the components of a computer that performs the four operations of the information
processing cycle (Figure 6).
Figure 3-6. Computer information processing cycle.
6. Computer Software. Computer software refers to sets of instructions, applications, or
programs that direct computers to perform a specific task or sequence of operations. For
example, disk operating software instructs the computer how to read a disk. Word processing
software enables the computer user to add pictures to correspondence. Plainly spoken, word
processing software is used to create and print documents. Budget, payroll, and tax software
enable the user to keep an automated budget, write checks, pay employees, and track and pay
taxes electronically. As you can see, software gives you flexibility when using a computer.
Without software, your computer would just be another dust collector.