User interaction refers to the ways in which users engage with a system, application, or device. This can include actions like clicking buttons, entering data, or navigating through menus. Effective user interaction design aims to create a seamless experience that allows users to accomplish their tasks efficiently and intuitively. Key elements of user interaction include usability, accessibility, and feedback. Usability ensures that the system is easy to use, while accessibility makes it available to people with different abilities. Providing clear feedback helps users understand the results of their actions, enhancing their overall experience.