Computer Applications in Business [BC-302] Web ref. www.hcc.edu.pk/it

SOFTWARES Computer software, or just software, is a collection of computer programs and related data that provides the instructions for telling a computer what to do and how to do it.  COMPUTER PROGRAM A computer program is a sequence of  instructions written to perform a specified task with a computer.

Types of Software System Software Applications Software Utility Programs

System Softwares System software - software designed to operate the computer hardware and to provide a platform for running application software. Windows, Linux , Mac operating systems.

Application Softwares Application software - software designed to help the user to perform specific tasks Examples: Ms-Office Quick Book Games Flights Management System

Utility Programs Utility software is system software designed to help analyze, configure, optimize or maintain a computer. Examples Anti-virus,   Backup Programs, Cryptographic programs, Data compression  Data synchronization, Disk defragmentation,  On Screen Keyboard, Navigator program, magnifier, Disk partitions 

COMPUTER LANGUAGES In all over the world, language is the source of communication among human beings. Different countries/regions have different languages. Similarly, in order to communicate with the computer user also needs to have a language that should be understood by the computer. For this purpose, different languages are developed for performing different types of work on the computer.

Types of Programming Languages Low Level Languages (machine codes ) Machine Language Assembly Language High Level Languages JAVA C++ C Query Language SQL

Machine Language Machine language is the only language that a computer understands. Each statement in a machine language program is a sequence of bits. Each bit may be set to 0 or 1. Series of bits represent instructions that a computer can understand. For example, the number 455 is represented by the bit sequence 111000111. Machine code is sometimes called native code

Machine Language (Continue) Machine language is a low-level programming language. It is easily understood by computers but difficult to read by people. This is why people use higher level programming languages. Programs written in high-level languages are compiled and/or interpreted into machine language so computers can execute them.

Assembly Language Assembly language is a representation of machine language. In other words, each assembly language instruction translates to a machine language instruction. English support is given to this language The advantage of assembly language is that its instructions are readable. For example, assembly language statements like MOV and ADD are more recognizable than sequences of 0s and 1s. Though assembly language statements are readable, the statements are still low- level.

High-level language High-level languages are what most programmers use. Languages such as C, C++ and Java are all high-level languages. One advantage of high-level languages is that they are very readable. The statements in these languages are English-like.  A single statement in a high-level language can translate into many machine language statements. Finally, high-level languages are usually portable.

High Level Language (continue) A disadvantage of high-level languages is that they are usually less powerful and less efficient. Since statements are high-level, you cannot code at the bit level the way you can with assembly language. High-level languages also need to be compiled and/or interpreted into machine language before execution.

QUERY LANUAGE Query languages are computer languages used to make queries into databases and information systems. FOR EXAMPLE structured query language Select F-Name from Customer where NIC=373737. Customer (Table) NIC F-Name L-Name DOB City 457283 Maria Anders  11-09-12 NY 373737 Paula Wilson  09-04-12 NZ

Conclusion That is a basic description of the three basic types of programming languages. Until people can process information like computers, we will leave machine language to computers and use high-level programming languages instead. Example 10001010100010100110010101010 (machine code) ADD, MOVE 3,4 (assembly code) ADD TWO NUMBER A AND B (High Level Code) Select first-name from table customer (Query Language Code)

Languages Processors Assembler Compiler Interpreter

Assembler An assembler is a program that takes basic computer instructions and converts them into a pattern of bits that the computer's processor can use to perform its basic operations. Some people call these instructions assembler language and others use the term assembly language.

Compiler A compiler is a special program that processes statements written in a particular programming language and turns them into machine language or "code" that a computer's processor uses. Typically, a programmer writes language statements in a language such as Pascal or C one line at a time using an editor .

Compiler The act of transforming source code into machine code is called "compilation".  The compiled program took ten minutes to run to completion. The interpreted program took an hour. Examples: Before the game could be tested it had to be compiled.

Interpreter In computing, an interpreter is a computer program that reads the source code of another computer program and executes that program. Because it is interpreted line by line, it is a much slower way of running a program than one that has been compiled