I wanted to approach the question of "what is Stateless exactly in REST" with the following question title because of the following notes I've gathered:
To be "Stateless" means that the user must always supply the necessary information in the request for the server to process.
Because of that fact, a client can contain number of identifiers such as, authentication key to be passed in every request to know who is the user. (Without knowing of his existence)
When the client asks for a list of orders for his business, the server can know which resource to fetch the information from and how to filter it using the User Id.
in ASP.NET Sessions, a client must provide a "Session Id" cookie in order to load the Session data in the first place. So again, the client provides the necessary data for the server to process. ASP.NET just prepares the endpoint method with cached session data to be used for the process. An example of that usage would be to which sub-user the client is logged into.
This is what got me confused, since in some articles about REST, the "Stateless" rule means that no session shall be stored in server about the client. For example "The server will not store anything about the latest HTTP request.... No session, no history"
My only example (of breaking the rule "properly") that I can think of is a case where you need to process ONE ACTION by multiple requests.
What can be described as an example of a service that completely breaks the REST rule of being stateless?