Computer - Software

 Software

        Till now, we have studied about the physical components or the hardware of the computer system. But the hardware is of no use on its own. Hardware needs to be operated by a set of instructions. These sets of instructions are referred to as software. It is that component of a computer system, which we cannot touch or view physically. It comprises of the instructions and data to be processed using the computer hardware. The computer software and hardware complete any task together.

        The software comprises of set of instructions which on execution deliver the desired outcome. In other words, each software is written for some computational purpose. Some examples of software include operating systems like Ubuntu or Windows 7/10, word processing tools like LibreOffice Writer or Microsoft Word, video player like VLC Player, photo editors like Paint and LibreOffice Draw. A document or image stored on the hard disk or pen drive is referred to as a softcopy. Once printed, the document or an image is called a hardcopy.

 1. Need of Software

        The sole purpose of a software is to make computer hardware useful and operational. A software knows how to make different hardware components of a computer work and communicate with each other as well as with the end user. We cannot talk to or instruct the hardware of a computer directly. Hence, software acts as an interface between human users and the hardware.

        Depending on the mode of interaction with hardware and functions to be performed, software can be broadly classified into three categories viz. i) System software ii) Programming tools and iii) Application software. The categorisation of software is shown in Figure 1.9.

2. System Software

        The software that provides the basic functionality to operate a computer by interacting directly with its constituent hardware is termed as system software. A system software knows how to operate and use different hardware components of a computer. It provides services directly to the end user, or to some other software. Examples of system software include operating systems, system utilities, device drivers, etc.

 (A) Operating System

            As the name implies, operating system is a system software that operates the computer. An operating system is the most basic system software, without which other software cannot work. The operating system manages other application programs and provides access and security to the users of the system. Some of the popular operating systems are Windows, Linux, Macintosh, Ubuntu, Fedora, Android, iOS, etc.

(B) System Utilities

            Software used for maintenance and configuration of the computer system is called system utility. Some system utilities are shipped with the operating system, for example disk defragmentation tool, formatting utility, system restore utility, etc. Another set of utilities are those which are not shipped with the operating system but are required to improve the performance of the system, for example, anti-virus software, disk cleaner tool, disk compression software, etc.

 (C) Device Drivers

        As the name signifies, the purpose of a device driver is to ensure proper functioning of a particular device. When it comes to the overall working of a computer system, the operating system does the work. But everyday new devices and components are being added to a computer system. It is not possible for operating system alone to manage all of the existing and new peripherals, where each device has diverse characteristics. The responsibility for overall control, operation, and management of a particular device at the hardware level is delegated to its device driver.

            The device driver acts as an interface between the device and the operating system. It provides required services by hiding the details of operations performed at the hardware level of the device. Just like a language translator, a device driver acts as a mediator between the operating system and the attached device.

3. Application Software

        The system software provides the core functionality of the computer system. However, different users need the computer system for different purposes depending upon their requirements. Hence, a new category of software is needed to cater to different requirements of the end-users. This specific software that works on top of the system software is termed as application software. There are again two broad categories of application software: general purpose and customised application software.

(A) General Purpose Software

        The application software developed for generic applications, to cater to a bigger audience in general are called general purpose software. Such ready-made application software can be used by end users as per their requirements. For example, spreadsheet tool LibreOffice Calc can be used by any computer user to do calculation or to create an account sheet. Adobe Photoshop, GIMP, Mozilla web browser, iTunes, etc. fall in the category of general purpose software.

 (B) Customised Software

            These are custom or tailor-made application software, that are developed to meet the requirements of a specific organisation or an individual. They are better suited to the needs of an individual or an organisation, considering that they are designed as per special requirements. Some examples of user-defined software include websites, school management software, accounting software, etc. It is similar to buying a piece of cloth with specific color and fabric and get it stitched as desired.

Proprietary or Free and Open Source Software

            Developers of some software allow public to freely use their software along with source code with an aim to improve further with each other’s help. Such software is known as Free and Open Source Software (FOSS). For example, the source code of operating system Ubuntu is freely accessible for anyone with the required knowledge to improve/add new functionality. More examples of FOSS include Python, Libreoffice, Openoffice, Mozilla Firefox, etc. Sometimes, software are freely available for use but source code may not be available. Such software is called freeware. Examples of freeware are Skype, Adobe Reader etc.

            When software to be used has to be purchased from the vendor who has the copyright of the software, then it is a proprietary software. Examples of proprietary software include Microsoft Windows, Tally, Quickheal etc. A software can be freeware or open source or proprietary software depending upon the terms and conditions of the person or group who has developed and released that software.