This is not the place to ask that question. Use the Information Center
to find basic system information. This site is for problem assistance.
Tom

Anyone please give a small explanation as i needed..    Surey.

What a list of questions, are these interview questions?

“Why we need that?”

We don’t know whether you need it or not.

Not exactly Phil…
These are not interview questions.
Just i want to do one project,so before that i need to know about some concepts clearly.. that’s why..

Surey

Just i want to do one project,…
 
Is this project for new development? Or is it maintenance on old existing code?
 
The questions you’ve been asking are about old and almost obsolete commands. They probably shouldn’t be part of anything new.
 
If the project is about old code and you see those commands being used, we need to see the code so we have an idea why they were used. Most likely they were used because there was no good alternative at the time the code was written. It’s also possible that the code was written by someone who didn’t know better.
 
For this question, you asked about INZPFM which is the ‘Initialize Physical File Member’. You use it when you want to initialize a physical file member, just like its description (in the Information Center) says and like its help text says. We can’t tell you more than what is already given to you in those sources.
 
But I don’t know why you would want to initialize a physical file member unless maybe you were creating test data.
 
You asked why you need it. Well, I don’t need it at all. I’ve never seen it used. I would need to see possibly the entire application to figure out why that application needed it. I would almost certainly design the application so that it wasn’t used at all. If I saw it being used, I would start by thinking that the application was poorly designed.
 
I expect that it provides a function that supports some type of System/36 application. A developer more familiar with S/36 might know more. Except for old code, I don’t know any reason to know much about S/36 now.
 
None of that is very helpful to you, but that’s part of why I keep saying that this isn’t the right place to ask those questions. The answer to every one of your questions is the same. If you ask why you need a command, the answer is always that you need it because you need what the command does. But I can’t know why you need what any command does. I don’t know what your applications or projects need.
 
Tom

23 years as an as/400 developer, never used INVPFM, don’t feel that I’ve missed anything.  You go for it.  Teach us when/why we need it.Phil