Add scrolling images or text to your website with the Bootstrap carousel component.
The Bootstrap carousel component enables you to add scrolling images and text that slide in, pause, then slide out. Controls enable the user to scroll forwards or backwards within the set. Basically a scrolling marquee with user controls.
Explanation
To create a basic carousel:
Apply .carousel and .slide to an outer container (with its own ID).
For the scrollable contents, wrap all items in a .carousel-inner and give each item a .carousel-item class.
Also, you must apply .active to one of the slides in the carousel, otherwise the carousel won't be visible. This class allows you to set one slide as the initial slide (i.e. the starting slide).
Add Controls
To add "Previous/Next" controls, use an <a> with .carousel-control-prev or carousel-control-next. Also add a <span> with .carousel-control-prev-icon or .carousel-control-next-icon.
To cater for screenreaders, add <span>s with the words "Previous" or "Next" and give them the .sr-only class. This will hide this text from browsers, but read out the text in screenreaders.
Add Indicators
To add "indicator" controls (the little clickable areas at the bottom, center), add a list with .carousel-indicators, as well as the applicable .data-target and .data-slide-to attributes.
Captions
You can add captions to your slideshow by adding a <div> with the .carousel-caption class applied. This goes inside each .carousel-item.
Bootstrap 4 vs Bootstrap 3
Bootstrap 3 uses .item for each carousel item.
Bootstrap 4 uses .carousel-item for each carousel item.