What holds on your feet on a snowboard?

Answer 1

In short: bindings.

First, there are snowboard boots. They are stiffer than your average winter boots, but aren't like ski boots in that they are not constructed out of solid parts. The closest analogy I can think of is a loose or soaked cast. They're just stiff enough to let the bindings, which are attached to the board hold your feet tight in them without traumatizing you.

ANSWER:

The one that holds your feet on a board is your bindings. You have to wear your snowboard boots then place the bindings after.