Which of the following is NOT a characteristic of an application window?

An application window is primarily designed to facilitate user interaction with the software, managing how tools, content, and features are displayed. A key characteristic of an application window is that it can contain a menu bar, which provides access to various functions and options available within the application. This helps users navigate the different features.

Additionally, many application windows support a multi-tab interface, allowing users to work with different documents or pages simultaneously within the same window, enhancing productivity and organization. Furthermore, application windows can display multiple panels, each serving different functions or presenting different kinds of information for the user.

Storing user data, however, is not a characteristic of the window itself; rather, it pertains to the application's overall functionality and data management capabilities. An application may have the capability to save user data, but this happens at a higher software level, often involving databases or files rather than within the window structure. Thus, not being a characteristic of the application window itself, this makes it the correct choice in this context.