Program :

                      Program is a set of instructions written in programming language to perform a specified task.

 Programming:
                  The process to give instructions to the computer is called programming .

 Programmer:

                        The person who is involved to  prepare a computer program is called programmer.

 System programmers:

                                                            The person who writes program to boot the computer to control the hardware components  etc are called system programmers.

 Application programmer:

                                                                  Appication programmer are used to design a application program to fulfill a specified task.

  Programming language:

                                                                        The language which is used to write programs for the computer is called programming language.

  Machine language:
                                The first language of computer was binary language, which is also known as machine language.

                                                                                            
  Assembly language:                                       
                                 Due to the complexities of machine language in the early 1950’s IBM company with contribution of computer scientists developed another language, which is known as assembly language.

  High level language: 

                                                          In the early 1960’s different languages were developed and used in the third generation of computers which are known as High level language.

  Compiler:

                         Compiler is a language translator that translates the program written in high level language to machine language at once.

  Interpreter:

                             Interpreter is a language translator that translates the program written in high level language to machine language statement by statement.

  Assembler:

                            Assembler is a language translator, which translates an assembly language program into its equivalent machine language program.  

  Fourth generation language:                                                            Fourth generation languages are closer to human languages than typical high level programming language.

  Advantages of machine language:

·                     Machine language is directly understood by the computer so the program written in machine language does not need to be converted.

·                     The program developed using machine  language becomes extremely fast since   no conversion is required.

      Disadvantage of machine language:

      

·                     Programming using machine language is difficult to write and remember.

·                     A machine language is machine dependent. Machine codes depend upon the architecture of the computer.

·                      It is time consuming and tedious task to modify the program written in machine language.

      Advantages of Assembly language:
                    

·                       As assembly language uses symbols and mnemonic codes it is easy  to understand write and modify program  in assembly language.

·                      It is easy to find out errors in the programs written in assembly language.

·                     The program written in assembly language executes faster because it is closer to the machine.

            

     Disadvantage of Assembly language:

·                     A assembly language  is also machine dependent language.The  program  written for one type of  computer has to be modified to use in another type of computer.

·                      Since assembly language is machine   dependent,the programmer must have   knowledge of hardware.

·                     The program written in assembly language is less efficient.The assembly  program takes more time to execute  than the machine codes program.

     Advantages of High level Language:

·                     As high level language are closer to English language, they are easy to  learn and use.

·                     High level language are machine independent.so,It is easy to write and  modify programs written in high  level   language.

·                     It is easy to do documentation of high level program.

·                     It is faster to write programs in the high level language.

     Disadvantage of High level language:

·                     High level programs takes more time to execute in computer.

·                      Programs written in high level language  must need language processors   to convert  into  machine  language.