Intro System Softwrae

Software

Computer software, or just software, is a collection of computer programs and related data that provides the instructions for telling acomputer what to do and how to do it. Software refers to one or more computer programs and data held in the storage of the computer for some purposes. In other words, software is a set of programs, procedures, algorithms and its documentation concerned with the operation of a data processing system. Program software performs the function of the program it implements, either by directly providing instructions to the computer hardware or by serving as input to another piece of software. The term was coined to contrast to the old term hardware(meaning physical devices). In contrast to hardware, software "cannot be touched".^[1] Software is also sometimes used in a more narrow sense, meaning application software only. Sometimes the term includes data that has not traditionally been associated with computers, such as film, tapes, and records.

Types of Software

System software

System software provides the basic functions for computer usage and helps run the computer hardware and system. It includes a combination of the following:

§  Device drivers

§  Operating systems

§  Servers

§  Utilities

§  Window systems

System software is responsible for managing a variety of independent hardware components, so that they can work together harmoniously. Its purpose is to unburden the application software programmer from the often complex details of the particular computer being used, including such accessories as communications devices, printers, device readers, displays and keyboards, and also to partition the computer's resources such as memory and processor time in a safe and stable manner.

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.

Application software

Application software is developed to perform in any task that benefits from computation. It is a broad category, and encompasses softwareof many kinds, including the internet browser being used to display this page. This category includes:

§  Business software

§  Computer-aided design

§  Databases

§  Decision-making software

§  Educational software

§  Image editing

§  Industrial automation

§  Mathematical software

§  Medical software

§  Molecular modeling software

§  Quantum chemistry and solid state physics software

§  Simulation software

§  Spreadsheets

§  Telecommunications (i.e., the Internet and everything that flows on it)

§  Video editing software

§  Video games

§  Word processing

Components of System Software

System software is designed to operate the hardware of the computer. It also provides platform for running application software and basic functions for the computer usage. The purpose of system software is to protect the applications programmer from the complexity and specific details of a particular computer being used, especially memory and other hardware features. It consists of the following components:

Device Driver:
This is a computer program that allows higher level computer programs in interacting with the computer hardware. A device driver simplifies programming as it acts as a translator between a hardware device and the applications that use it.

Operating System:
An operating system manages computer hardware, provides services for execution of application software. It consists of programs and data. Examples of operating systems for computers are Linux, Microsoft Windows, OS X, Unix.

Server:
A server is a program that operates as a socket listener in computer networking. A server computer is a computer, or series of computers, that link other computers and they often provide essential services across a network, either to private users inside a large organization or to public users via the internet.

Utility Software:
Utility software is used to manage the computer hardware and application software and performs small tasks. Some of the examples of utility software are systems utilities, virus scanners and disk defragmenters.

Windowing System:
A windowing system supports the implementation of window managers and provides basic support for graphics hardware and pointing devices such as mouse, and keyboards. It is a component of graphical user interface.

Features of system software

1. faster in speed.

2. It allows the use of system programming.

3. It is machine dependent.

4. difficult to manipulate.

5. difficult to design.

6. Complex tasks.

Compiler vs. Interpreter

An interpreter translates some form of source code into a target representation that it can immediately execute and evaluate. The structure of the interpreter is similar to that of a compiler, but the amount of time it takes to produce the executable representation will vary as will the amount of optimization. The following diagram shows one representation of the differences.

Compiler characteristics:

·       spends a lot of time analyzing and processing the program

·       the resulting executable is some form of machine- specific binary code

·       the computer hardware interprets (executes) the resulting code

·       program execution is fast

Interpreter characteristics:

·       relatively little time is spent analyzing and processing the program

·       the resulting code is some sort of intermediate code

·       the resulting code is interpreted by another program

·       program execution is relatively slow

The above characteristics are typical. There are well-known cases that are somewhere in between, such as Java with it's JVM.