CPI Communication in IBM I (AS400)

Question

Recently I came across a thing called CPI Communication (common programming interphase) in one of a rpgle program I was working on. Instead of calling other programs directly they are using something called CPI for making the same call. I was just told that is a more efficient way of calling than a normal call. Can someone kindly explain in simpler terms what is the difference between CPI and a normal static or dynamic call?

Answer 1

check out this link

( I have removed the rest of my answer as it was wrong. )