Breadcrumbs are a navigational feature that helps users understand their current location within a website's structure and navigate easily to previous sections. They typically appear as a row of small text links at the top of a page, indicating the path from the home page to the current page. This feature enhances user experience by providing a clear way to backtrack and explore other sections of the site. Breadcrumbs are also beneficial for SEO, as they create a natural internal linking structure that helps search engines understand and index the website's hierarchy.