Software And Computer Program

Software

In loose terms, software refer to computer programs which serve as interface between the user and the hardware. Software can be categorized into two, namely:

1. System Software

- including operating system, compilers, linkers etc.

2. Application Software

- including word processor, spreadsheet, calculator etc.

Computer Program

A computer program is very much like an algorithm. However, it may not be finite, i.e., a program need not terminate after a finite number of steps. An example of such a program is an operating system.

Basically, a computer program is made up of two components:

1. Data

2. Instructions for manipulating data

A computer program is written using a certain computer programming language.

Computer Programming Language

A programming language describes the:

1. vocabulary (set of symbols and words)

2. syntax (rules)

3. semantics (meaning)

that are used to write a valid computer program.

Types of Computer Programming Languages

1. Low-Level Languages

Low-level languages include:

- machine language (lowest level, defined in terms of zero's and one's)

- assembly language (uses mnemonics)

They are called low-level because they require the programmers to have a good understanding of the underlying hardware for which the programs are intended to run

Programs written using low-level languages are not portable, i.e. they cannot be executed in two different and incompatible processors

2. High-Level Languages

High-level languages include:

- FORTRAN

- ALGOL

- COBOL

- PL/1

- BASIC

- Pascal

- C++

- Java

They are called high-level because (1) the language is quasi-English and (2) it does not require the programmer to know the actual computer hardware

The programs written in high-level languages are able to exhibit portability