How to know if my code requires a Fortran redistributable or Fortran Compiler?

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According to PSSE documentation, Fortran redistributable is sufficient to "use" user defined models supplied to you by others, but if you want to "compile Fortran code" you would need a Fortran compiler. However, my confusion is that sometimes models are sent as .obj and .lib files and would need to be compiled to dsusr.dll using Cload.bat. In this case, is the redistributable sufficient? or do I need the Fortran compiler?

Also, in general how do I know if Fortran redistributable is sufficient or I need Fortran Compiler?

(Apologies if this sounds like a basic question, but I am very new to Fortran)