History Explanation

          *  In the year  1969 an assembly language was 
              implemented,which was not  programming language.
          *  This assembly language was developed by using unix os,   
               at bell labs.
          *   In the year  1970 the first  programming language was
              implemented.It was named b-language, as it  was
              basic programming language.                
          *  In the year  1971 some of the new features  were added      
              into the old  language that became partially
              c-language. 
          *  In the year  1972 C-language was completed by
              "Dennis Ritchie" at bell labs.