In RESTFUL Service, ST itself defines State Transfer and the properties beign stateless means complete closing off. It means, the state of the client's application is never stored on the server and is passed on.
In this process, the client's send all the information that is required for the server to fulfill the HTTP request that has been sent.
Thus every client request and the response is independent of the other with complete assurance of providing required information
Every client send Session identifier which also executes as an identifier for each session
So, while you accessing HTTP Verbs you have to pass or get the relevant stuff from client area like session identifier values from Cookie and then pass it to server to process.