Which factor describes how easy it is for users to navigate and use an app?

The factor that describes how easy it is for users to navigate and use an app is usability. Usability refers to the user-friendliness of an application, focusing on how effectively and efficiently a user can achieve their goals while using the app. Key elements of usability include intuitive design, clear instructions, and the simplicity of navigation, all of which contribute to a positive user experience.

In contrast, accessibility pertains to how well an app can be used by individuals with disabilities, rather than the general ease of use for all users. Functionality refers to the specific features and capabilities of the app and how well it performs its intended tasks. Interactivity relates to the ways in which users engage with the application's content, but it does not directly address the ease of navigation and overall user experience. Thus, usability is specifically aligned with how navigable and functional an app is from a user's perspective.