What does stateless mean in the context of REST?

In the context of REST, stateless means that each request from a client to a server must contain all the information necessary for its processing, and the server does not store any state between requests.

This means that the server does not keep data about the client's session between API calls. For example, if a client has authenticated, it must send a token with each request so that the server can verify access rights without maintaining a session.

This approach simplifies scaling and increases fault tolerance, as any server can handle the request without depending on previous interactions.