FORTRAN is low level language. It was mainly invented to solve mathematical problems. It's had made the life of Mathematician very much easier in that time. We will discuss the main
structure of FORTRAN today. The main structure of FORTRAN contains three parts. They are the-
1.The Declaration Section: This section of the program consists of non-executable statements like program name and the variable types is declared in this part.
2.The Execution Section: This section consists of all kind of executable statements. All kind of mathematical equation are being written here.
3.The Termination Section: This section consists the program that terminate or stop the whole program.
PROGRAM program_name
IMPLICIT NONE
End Program
Here, IMPLICIT NONE is used to specified the type of variable. If we do not use IMPLICIT NONE, then FORTRAN language by default assume the variable starting with the letter i,j,k,l,m,n is integer type and other one is real. So, avoiding this confusion we use IMPLICIT NONE.
