Where are data usually stored in the system during request processing?

During request processing, data is usually stored in memory at the session or request context level. In Java, this can be:

• Local variables of the method handling the request.
• Attributes of the HttpServletRequest object for passing data between filters and servlets.
• Objects associated with the user session (HttpSession) if data needs to be preserved between requests.

For example, in a Java web application, data needed only for the current request can be placed in request.setAttribute("key", value). This allows data to be passed between components processing the request.

Thus, the main place for storing data during request processing is the RAM, in objects associated with the current request or session.