COMPUTER HARDWARE

[edit] Relationship to computer hardware
Computer software is so called to distinguish it from computer hardware, which encompasses the physical interconnections and devices required to store and execute (or run) the software. At the lowest level, software consists of a machine language specific to an individual processor. A machine language consists of groups of binary values signifying processor instructions which change the state of the computer from its preceding state. Software is an ordered sequence of instructions for changing the state of the computer hardware in a particular sequence. It is usually written in high-level programming languages that are easier and more efficient for humans to use (closer to natural language) than machine language. High-level languages are compiled or interpreted into machine language object code. Software may also be written in an assembly language, essentially, a mnemonic representation of a machine language using a natural language alphabet. Assembly language must be assembled into object code via an assembler.
The term "software" was first used in this sense by John W. Tukey in 1958.[4] In computer science and software engineering, computer software is all computer programs. The theory that is the basis for most modern software was first proposed by Alan Turing in his 1935 essay Computable numbers with an application to the Entscheidungsproblem
Practical computer systems divide software systems into three major classes: system software, programming software and application software, although the distinction is arbitrary, and often blurred.

[edit] System software
System software helps run the computer hardware and computer system. It includes:
device drivers,
operating systems,
servers,
utilities,
windowing systems,
(these things need not be distinct)
The purpose of systems software is to unburden the applications programmer from the details of the particular computer complex being used, including such accessory devices as communications, printers, readers, displays, keyboards, etc. And also to partition the computer's resources such as memory and processor time in a safe and stable manner.

[edit] Programming software
Programming software usually provides tools to assist a programmer in writing computer programs, and software using different programming languages in a more convenient way. The tools include:
compilers,
debuggers,
interpreters,
linkers,
text editors,
An Integrated development environment (IDE) is a single application that attempts to manage all these functions.