Frames allow dividing a webpage into multiple sections or frames, with each frame displaying a separate HTML document. Frames are commonly used to keep navigation menus or branding visible on the page while allowing the main content area to change. Some key uses of frames include a branding frame to identify the site, a navigational frame with hyperlinks, and a content frame for the primary webpage material. Frames provide advantages like keeping headers and menus visible as a user scrolls or loads new pages.