Carousel slider type is a little bit similar to the showcase slider type. The main difference between the two, that the WordPress Carousel slider has a pane where multiple slides can sit (Smart Slider 3 calculates the number of the slides which fits). When the slider switches to the next slide, in Carousel slider type the slider switches to the next pane instead.
Related Post: All You Need To Know About Carousel Slider Type
Related Documentation: Carousel slider type