Class 6 Computer Science Chapter 6 Computer Programming

There are many high level languages (HLL). Some examples of these are :
FORTRAN, COBOL, PASCAL, JAVA, C, C++
FORTRAN
Fortran stands for formula translation. This language is generally used by engineers.
COBOL
Cobol stands for common business oriented language. As it is clear by its name, it is used for business purpose.
PASCAL
PASCAL is a general-purpose language named after the great scientist Blaise Pascal. It is a very powerful computer language used to develop many application programs.
JAVA
Java is a modern day language developed by Sun Microsystems. It is used widely nowadays. It also uses the concept of object-oriented programming.
C
C is also a powerful computer language which uses structured programming approach. It is used widely for developing numerous applications.

A program is always well defined. It consists of:
1. Variables
2. Statements
We human beings use and understand our natural languages. Computer is a man made machine. But computer does not understand the human languages. It only understands machine level language. Therefore, specific languages are developed for computers. A program is written in some specific language called a programming language.

Programming languages are divided into the following types:
• Low Level Language (LLL)
• High Level Languages (HLL)
Low level languages are machine oriented languages. These are directly understood by the computer. These languages are generally machine dependent.
Low level languages are of the following types:
• Machine level language (MLL)
• Assembly level language (ALL)

MACHINE LEVEL LANGUAGE
You already know that a computer can understand only digital language, which is also known as binary number system. The binary number system uses only two digits 1 and 0. These two digits are called binary digits. The language, which uses binary digits is called the machine level language.

In assembly level language we use letters and symbols instead of binary digits. These symbols are called Mnemonics. Programs written in assembly level languages are called assembly codes and these assembly codes are translated into machine level language instructions. Assembly level language is easier to understand in comparison to machine level language.
HIGH LEVEL LANGUAGE (HLL)
It is easier for a human programmer to understand these languages as these languages are generally not dependent on any particular computer machine.

High level languages are designed in such a way that it does not create much pain or trouble for the programmers. These languages are not understood by the computer because it only understands 0 and 1. To make the computer understand a program, it is first converted into machine level language.
This job of translating a high level language into machine level code is done by a compiler or interpreter. This process is called decoding of programs.