The instructions to the computer are written in different languages. They are Low Level Language (Machine language), Assembly Language (Middle level language) and High Level Language (HLL). In Machine Language 0’s and 1’s are used to write , program. It is very difficult but this is the only language which is understood by the computer. In assembly language mnemohics (codes) are used to write programs.
Electronic Delay Storage Automatic Caleulator(EDSAC) built during 1949 was the first to use assembly language. In HLL English like statements are used to write programs. A – 0 programming language developed by Dr. Grace Hopper, in 1952, for UNIVAC-I is the first HLL.
A team lead by John Backus developed FORTRAN @IBM for IBM 704 computer and ‘Lisp’ developed by Tim Hart and Mike Levin at Massachusetts Institute of Technology. The other HLLs are C, C++, COBOL, PASCAL, VB, Java, etc. HLL is very easy and can be easily understood by the human being.
Usually programmers prefer HLL to write programs because of its simplicity. But computer understands only machine language. So there is a translation needed. The program which performs this job are language processors.