Phind is just prompt engineering, as is anything sitting on top of anything OpenAI is building right now - if you are doing Q&A then maaaaybe it does some resource augmented generation as well (say, from Stack Overflow or other technical resources)

Phind is often recommended to me by programmers who find it produces "better" results than a naive GPT-4 session, but I don't know that anyone has done any real world testing.