The key elements of UI design are:

Layout: The arrangement of elements on a screen to guide the user's eye and create visual hierarchy.

Color: The use of color to create contrast, highlight important information, and set the mood.

Typography: The use of typography to communicate information and create a sense of hierarchy.

Icons and Images: The use of icons and images to communicate information and add visual interest.

Navigation: The design of menus, buttons, and other interactive elements to help users navigate the interface.

Consistency: The use of consistent design elements to create a cohesive and recognizable interface.

Responsiveness: The design of the interface to be accessible and usable across different devices and screen sizes.