Foundation buttons have a number of parameters and styles — you can see a few examples below. The out of the box classes include size, type (color) and style (square, slightly rounded, and completely rounded).
Button classes can also be applied to button elements, as well as input type="submit" elements.
When you need a group of actions, button groups give you some easy-to-use options. These can have a class of .rounded or .even. You can even create button bars by using .button-bar.
These are useful when an action has several possible outcomes to select from, or when there are secondary choices you can make in lieu of a primary action.
If you need your dropdown to go up, simple add a class of .up to .button.dropdown.
Notice that in a split button, the span is the dropdown affordance and the main anchor is the primary button action.