Need of Software

The sole purpose of software is to make the computer hardware useful and operational. Hardware is inert circuitry; software is what brings it to life.

Software as the interface

Two facts explain why software is indispensable:

• Software knows how to make the different hardware components of a computer work — and how to make them communicate with each other as well as with the end-user.
• We cannot instruct the hardware of a computer directly. A human cannot talk to circuits; something must translate our intentions into hardware operations.

That "something" is software: it acts as an interface between the human user and the hardware. Every click, every typed command, every request passes through layers of software before it reaches the physical machine — and every result passes back through software before we see it.

The three broad categories of software

Software is classified by its mode of interaction with the hardware and the functions it performs. On that basis there are three broad categories:

1. System software — operates the computer itself by interacting directly with the hardware (covered in 1.7.2).
2. Programming tools — the languages, translators and development tools used to create new software (covered in 1.7.3). …