Tons of elements, pre-designed components, an icon library, community themes, the list goes on.
Very similar in end function to Bootstrap, but with arguably easier-to-use class names. Based explicitly around FlexBox, for naturally responsive pages.
A very different route, Tailwind provides a large number of utility classes that run through a preprocessor. This gives you the full power of writing ad-hoc styles on individual elements, but by making classes for them you can be certain
text-purple-500 is going to be consistent where used.
There are a few community-sourced component libraries available, but Tailwind UI by the Tailwind authors is growing constantly more robust.