Carousel

A carousel is a viewport onto a longer list. It shows one item, or a handful, and keeps the rest just outside the frame, where a set of controls (arrows, dots, a swipe, sometimes a timer) moves the window along. The items are peers: nothing about the second slide makes it a different kind of thing from the first, which is why the controls count and point rather than name.

That is the line between a carousel and tabs. Tabs label their panels, and the labels are the point: a reader picks the one they want and can come back to it. A carousel’s dots name nothing, so a reader can only step and see what turns up. Reach for tabs when the destinations are distinguishable, and for a carousel when the items are alike and there are more of them than the space allows.

Two other words get borrowed for this. “Slider” is the older web name for it, and it collides badly with the input control of the same name, so most vocabularies now say carousel and leave slider to the track and handle. “Gallery” usually means the grid view of a collection, where everything is visible at once and nothing is waiting off screen, which is the opposite trade.

The pattern’s poor reputation comes almost entirely from auto-rotation. Content that moves on its own reads as an advertisement and gets skipped, and it takes the item away from anyone who reads slowly or aims slowly. A carousel that rotates needs a stop control, and it needs to stop on hover and on focus. Even without a timer, very few readers ever see past the first slide, so nothing important should live only in slide four.