Explain the concept of Stateless applications and their main characteristics.

Stateless applications are applications that do not retain state between client requests. Each request is processed independently, without information about previous interactions.

Main characteristics of stateless applications:

• No storage of state on the server between requests.
• Scalability: easy to add new instances since there is no dependency on state.
• Easy recovery after failures, as there is no need to restore state.

Example: RESTful APIs are usually designed as stateless, where each HTTP request contains all the necessary information for processing (e.g., authentication data, parameters).

In Python, a stateless application can be implemented using frameworks such as Flask or Django, where the server does not store user sessions between requests, and all necessary information is passed in each request.