Each request is treated as a separate transaction in a stateless communication system. As a result, the server does not need to remember any session, identity, or status information that spans several requests from the same source. Similarly, the requestor cannot rely on the responder’s retention of such information.
A stateful communications protocol, on the other hand, is one in which the responder keeps track of “state” data (session data, identification, status, and so on) across numerous requests from the same source.
HTTP is a protocol that has no state. HTTP does not need the server to keep track of each user’s information or status across successive requests.
Different approaches are used by certain web servers to implement states (using cookies, custom headers, hidden form fields, etc.). However, HTTP, which is still a stateless protocol based on the fundamental request/response paradigm, remains at the heart of every online application.