As you saw in chapter 2 (types of computer
), computers come in many varieties, from the tiny computers built into household appliances, to the astounding supercomputers
have helped scientists map the human genome. But no matter how big it is or how
it is used, every computer is part of a system. A complete computer
system consists of four parts (see Fig. 1
Fig. 1: Four Parts of a computer.
The mechanical devices that make up the computer are called hardware. Hardware is any part of the computer you can touch (see Fig. 2
). A computer’s hardware consists of interconnected electronic devices that you can use to control the computer’s operation, input, and output. (The generic term device refers to any piece of hardware.)
Fig. 2: Computer Hardware.
The physical parts of a computer, which you can see and touch, are collectively called hardware.
Software is a set of instructions that makes the computer perform tasks. In other
words, software tells the computer what to do. Software, refers to the instructions, or programs, that tell the hardware what to do.
The term program refers to any
piece of software.
Fig. 3: Computer Software.
Some programs exist primarily for the computer's use to help it perform tasks and manage its own resources. Other types of programs exist for the user, enabling him or her to perform tasks such as creating documents. Thousands of different software programs are available for use on personal computers (see Fig. 3
Data consist of individual facts or pieces of information that by themselves may
not make much sense to a person.
A computer’s primary job is to process these
tiny pieces of data in various ways, converting them into useful information.
Fig. 4: Computer Data ( a piece of useful information).
For example, if you saw the average highway mileages of six different cars, all the different pieces of data might not
mean much to you. However; if someone created a chart
from the data that visually compared and ranked the vehicles mileages, you could probably make sense of it at a
glance (see Fig. 4
). This is one example of data being processed into useful information.
People are the computer operators, also known as users.
It can be argued that some computer systems are complete without a person’s involvement; however, no computer is totally autonomous. Even if a computer can do its
job without a person sitting in front of it, people still design, build, program, and
repair computer systems. This lack of autonomy is especially true of personal
computer systems, which are the focus of this subject and are designed specifically
for use by people.