Using UIkit you'll notice that many elements are made into inline stacks: Button, Image, Video and Height are a few examples. This approach allows these elements to be used into other stacks. As an example the Image stack can be used in Card, Slider, Slideshow etc. Another example are the Buttons that can be easily used in many stacks like the Navbar, Table and so on.
Navigations in Slider and Slideshow are also modular: you can use either the Dotnav, Slidenav and Thumbnav positioned anywhere into the container with the help of the Position stack.
Many elements are available as stand-alone stacks and as well as embedded into other ones. For example the Animation settings can also be found in Overlay, Position settings are also available in Background stack.