Most of the times the most difficult step it is the first one…
Every programing languages have differents statements to interpretate in code what you wants your programs do. To compile is the process to translate from text of source code written in a defined programming language to binary machine language, creating an executable program.
The process of develop a program have some main steps, define the flowchart of information, write the code, test and optimize.
The compilation commands are different if we are in the tests and debugging step or in the optimization step, because for tests of functionality the speed it is not an issue but it is possible to use the debugger and to easily understand where are the problems.
The basic structure of Fortran is:
end program <name>