picture inter and intra prediction

This question is regarding video coding standard MPEG/HEVC etc.
May I know on what basis a decision is made to encode a picture using intra or inter prediction method?
Thanks

Sharan-
I see that you're not getting any replies. Googling inter vs. intra prediction brings up lots of hits. One example I found explains what criteria H.264 uses, and advocates for computationally less complex methods:
https://link.springer.com/chapter/10.1007%2F978-3-...
This was in 2007, so no doubt for HEVC there are newer/better methods.
-Jeff

jbrower,
Thanks. I have seen multiple references. They explain pretty well how Intra and Inter prediction work in case of H.264 and H.265. However, I don't find description where it describes how an encoder decides to use one versus the other. I will continue to look at materials online.