Give each slide aria-roledescription="slide", and mark the container aria-live="polite" (or only announce on manual navigation). If autoplay is on, WCAG 2.2.2 requires a pause control — content that moves on its own steals reading time from low-vision or cognitively disabled users.
The difference from pagination, covered above, is what's being browsed — pagination splits list data into ranges, while a carousel cycles content itself, like images or promo cards, as slides. It shares a name with the range slider only by coincidence; they're unrelated components.
Arrow and dot buttons need clear labels — "Next slide," "Go to slide 2" — not just an icon.