HTTP (Hyper Text Transfer Protocol) regulates simple conversations between clients and servers, like placing an order in a restaurant. However, there are some gotchas like the server having short term memory requiring the client to repeat themselves. But don’t despair, HTTP helps reduce confusion with standardized requests and responses. By following these conventions developers are able to create amazing things not possible with just POST requests and 200 OK responses.
Details: http://www.meetup.com/South-Florida-PHP-Users-Group/events/148626432/