Hii folks i am having one question please don't mark this post as spam .I am just beginner in web services and need of a chat application on ios app .

I am using cake php for web services. i just want to know the keywords i mean how can i search for this topic i am having some keywords like socket and comet to built chat services .

please guide me just want to know how we can implement this not coding just hint me then i will Google for this .Also please tell me which one would be best because in my app while chat a user can send 10 sec video