You might have noticed that the compiler creates files with the mod file extension. These are what we call module symbol files.
A module symbol file contains information about the specification part of a Fortran module. The file name is made of the module name followed by the mod extension. For example, if your Fortran module is called weather , the compiler will generate a module symbol file called weather.mod . The same module symbol file can be used in 32-bit and 64-bit compilations, provided you add the required information to it.