Computer hardware
Hardware is the term used commonly to describe the components of a computer like the monitor, the keyboard, the hard disk, the floppy drive, C.P.U and the printer
Computer software
A computer cannot do things on its own. Its operation is purely based on the commands or instructions given to it by user. These set of commands and instructions together characterize a software. Software is another name for program. Software is codified in a manner which the computer indentifies and functions accordingly. In other words, software is a set of programs that enables the functioning of the hardware. There are two main types of computer software
1. Application software
A program or a set of programs designed to serve a specific purpose is called an application software. For example, if the task is computerization of the accounts of an institution, then all the programs designed for the said purpose will come under the range of application software
2. System software
It is a group of programs designed to control the activity of a computer system. System software helps to perform the various stages of application software in a cohesive manner. It co- ordinates the functions of the hardware components like the printer, the mouse, the memory and the C.P.U. It is impossible to utilise and applicaiton package without a system software. Those who prepare the system software are called system programmers
Types of programming languages
i) Low level languages
a) Machine level languages.
b) Assembly languages
ii) High level languages
a) Problem oriented languages.
b) Special purpose languages.
Machine level languages
To work at the level of the machine one has to use binary as the basic language for putting the instructions into the computer's memory.
Writing, testing and debugging of programs are extremely tedious. These are dependent on the computer.
Assembly languages
One step away from the machine level languages, these employ mnemonics and macros. Although assembly languages are very detailed and difficult to learn, they are the most powerful.
A one- to -one correspondence exists between an assembly language and a machine language of a computer. These are dependent on the computer
Problem oriented languages
These are designed to facilitate problem formulation in a manner which is as similar to the natural problem formulation as possible. These are supposed to be independent of the computer
The types of problems can be broadly classified into two types.
1. Business
2. Scientific
In business applications, the volume of data to be handled is extremely large. The type of calculations to be performed are relatively simpler and lesser in number and the language used is similar to English. example banking, financial accounting etc.
In scientific applications, the volume of data to be handled is quite less. The type of calculations to be performed are very complex and large in number and the type of language used is full of expressions and formulas.
For each instruction there are many machine level instructions generated before execution
Special purpose languages
These are designed for more narrow area than problem - oriented languages, for example - simulation and languages for processing alphanumeric data to determine the content or meaning of prose etc
Programs written in the high level language have to be translated into machine level language before execution. These developments have significantly increased the number and diversity or the computer users population
Interpreters and compilers
The program written in the assemble or high level language is called the "Source" program.
The source program must be converted into an equivalent machine level program. The machine language program is called the "Object" program.
This conversion or translation is done with the help of a translation program.
An interpreter is a program that, instruction by instruction, converts the source program into machine language. It directly passes the machine language instruction to the computer for execution before the next source program instruction is processed. It is very convenient for beginners to work with an interpreter language like BASIC.
A compiler is a translation that converts its associated high - level language instructions into machine language instructions on a one- to many basis. It converts the entire source program into machine language and then passes it to the computer for execution. The translated program can be stored separetely and executed directly with out having to translate it every time as in the case of an interpreter.
Flow charts
Flow chart is a diagram which consists of a set of boxes joined by arrows. Arrows denote the various steps involved in a process. It must be prepared prior to any computer programming. Flow chart helps to check any error or lapses in the programs. There are certain formats, approved by the international standard organisation for preparing flow charts which must be adhered to.
Binary number system
Characters are stored in the computer in a coded format using the binary number system. This is because the very funcitoning of electrical and electronic components take place in the binary format. A computer is primarily made up of electrical and electronic components. These components actually are either in On or Off position always. A transistor for instance is either in the conduction or non - conducting mode. The binary format 0,1 is best equipped to denote these signals. And it is therefore ideal to store every form of data in the binary number mode using 0,1. The circuit of the computer is also designed to accept data in the binary format.
In short, computers can understand data only in its binary form.