You seem to want the answers to both the following questions:

What are the differences between perl on unix/linux and on Windows?

What are the differences between unix/linux and Windows?

The answer to the 1st question is answered in perl's own docs, but the major one is that fork() on Windows is implemented as threads.

The answer to the 2nd question is long and involved and frankly expecting someone to type 'em all out for you is abusive.

If you hope to write cross-platform code, avoid using external programs where you don't have to and use the many excellent modules built for the purpose.