What does the term 'stateless' refer to in the context of web services?

In the context of web services, the term 'stateless' refers to a service that does not maintain any state between requests. This means that each request from a client to the server is treated as a new and independent transaction, without any knowledge or dependence on previous interactions. Stateless services do not store data about prior requests, which allows them to be more scalable and flexible, as they can handle a greater number of requests without the overhead of managing session information.

This design simplifies the service architecture, as the server does not need to keep track of the individual state for each client. Clients are responsible for sending all necessary information with each request. This feature is key in many web services, such as RESTful services, where scalability and performance are often prioritized.

In contrast, services that maintain state between requests create a persistence layer that can complicate the service architecture, as they need to manage client sessions and the data associated with them, which is not the case for stateless services.