A carousel is a UX component that displays content in a slideshow-like manner. Large, above-the-fold carousels often contain a page's Largest Contentful Paint (LCP) element, and therefore can have a significant impact on LCP. In addition, a surprising number of carousels use non-composited animations that can contribute to Cumulative Layout Shift (CLS). On pages with autoplaying carousels, this has the potential to cause infinite layout shifts.
To learn about performance and UX best practices for carousels, see Carousel Best Practices.