Introduction

Software and its Components

Introduction

Today, everyone is affected by the widespread use of software, either as a user or as a professional who builds it. Users need to appreciate the advantages of using software, while software professionals need to understand its unique characteristics so that they can build high-quality software products and execute software projects successfully.
In this section, you will learn what software is and what its components are.

Widespread use of software

Software is used in all spheres of life. It is used in offices for running businesses effectively, in factories for manufacturing, and in households for various devices. Some examples of equipment that uses software are mobile phones, microwave ovens, military equipment, and airplanes.
The design of an airplane today involves thousands of experts and the use of special CAD software. Also, flying the plane depends on software. For example, a Boeing 777 is operated using 4 million lines of code. A lot of effort goes into ensuring that this code is
error-free. Guru Edward Yourdon, in his book, Death March, states that the Boeing 777 can be regarded as 'a bunch of software with wings'.
Let us further explore what software is.

What is software?

We know that word processors, payroll packages, and operating systems are software because they enable us to use the abilities of computers to perform work.
On the other hand, floppies and CDs are media used to store software. Desktop computers, modems, and communication cables are hardware that enables the software to provide various functionalities.
Based on your understanding of what software is, would you consider a Web site as software?

Some definitions of software

Now that you have some idea of what software includes, let us discuss some standard definitions of software.
IEEE Std.610.12-1990 defines software as 'computer programs, procedures, and possibly associated documentation and data pertaining to the operation of a computer system'.
According to Webster's New Collegiate Dictionary (1975), software is 'an entire set of programs, procedures, and related documentation associated with a system, and especially a computer system'.
These definitions provide a perspective of what software encompasses. You can see that the emphasis in these definitions is on 'programs', which are essential components of software and contain instructions for the computer. In addition, software consists of the data and documentation needed for operating the programs.

A comprehensive definition of software

Software can be defined comprehensively as consisting of the following three components.

• Programs (instructions): This component provides the desired functionality and performance when executed.
• Data: This component includes the data needed to drive and test programs and the structures required to hold and manipulate this data.
• Documents: This component describes the operation and use of programs.

When you build software, you must create not only programs but also data and documents. A collection of these three components is called configuration. When you manage these three components, you perform a function that is called configuration management.