Computer Operations

The computer performs two types of operations on data: arithmetic and logical. Arithmetic operations are simply addition, subtraction, multiplication, and division, as in adding the numbers 2 and 2. Logical operations compare values to perform logical tests and make decisions. For example, is the number 2greater than (expressed with the > sign) or less than (expressed with the < sign) the number 6? As you can see, the fundamental way computers operate is very simple.

The Five Data Processing Steps

We can now put everything we've just learned into a practical context and more clearly understand how the computer performs its tasks. There are five specific steps involved in processing data with a computer: input, processing, output, storage, and results.

When we give the computer either instructions or data, it is called input. An instruction is either an arithmetic or logical operation, such as addition. The data are the numbers, such as 2 and 2. The computer performing the addition of 2 and 2 is processing, as you have already learned. The product of the processing, or the answer we seek, is termed output; in our case, the number 4.

Once the data is processed and output from the computer, there are two additional steps. One is storage, or holding the data in computer memory. This may be for a short, indefinite period, or permanently, depending on the type of storage we choose. The final step is called results, or presenting the data in a form that a person can use. Most commonly, the results are displayed on the monitor or printed on the printer.

The five data processing steps.

1. input: Either instructions or data.

2.Processing: The computer performing its instructions—either an arithmetic or logical operation—on the data.

3.Output: The data produced after processing.

4.Storage: The option of retaining the data indefinitely or permanently.

5.Results: Presenting the data in a useful form.

Needless to say, we don't often use the computer to perform the tasks a calculator can do. However, this example of adding 2 + 2 demonstrates the simplicity of the computing process. The computer is no more complicated than this; its primary virtue is its speed. It is able to count and compare its binary digits very, very fast.

Software

Software is the programs and instructions that tell the computer what to do. The programmer is a person who understands the problem or task the computer is supposed to work on and can translate it into the language the computer understands. This process is called programming. Programmers, in the programming process, create software.

Computer software takes two forms. One is system software, which controls the computer's primary operations. The system software we most commonly come in contact with is called the operating system which, among other jobs, controls the programs we use to accomplish our tasks.

The other form computer software takes is application software, the programs we use to produce useful work. This might be a bicycle parts inventory management application program or a zoological classification application program. There are applications for many thousands of interests and needs. The three most commonly used for personal productivity, schoolwork, and business are:

■ Word processing, which lets you create and revise your writing.

■ The spreadsheet, which lets you perform a variety of accounting and mathematical calculations.

■ The database management system (DBMS), which lets you organize and obtain data stored in one or more databases.

Therefore, programmers create the application software that we use to issue instructions to the computer in order to perform various tasks. The tasks we perform are often referred to as procedures, a set of clearly defined steps. When those procedures are applied to working with data, the result is information that we and others find useful in a variety of ways.

Knowledge Check:

1. What is data processing?

2. What are the two types of computer operations?

3. What are the five data processing steps?

4. What are the two kinds of software?