Who and what field? If you mean programmers and regular HN visitors then no, those words have no meaning for me. What does each one mean and why is it important

Who and what field? If you mean programmers and regular HN visitors then no, those words have no meaning for me. What does each one mean and why is it important for running medical trials? Other than protocol writing, which sounds like a list of rules, I have no idea what the rest means or why it would be important in a trial.