billions of small particles whizzing about in space, but slower than the air surrounding the box and any liquid that happens to be in or around the box. As far as the actually "wood" part is concerned, there is probably some phloem, cambium, sapwood, heartwood, and pith. And the tree grows because of nutrients in the soil created by bacterium digesting organic matter (like wood and leaves and animals). The box is made by a human (since as far as I know there isn't a "wooden box" tree in the world dropping premade boxes instead of leaves or needles or cones or nuts), so there is some intelligence involved, too. And it is either held together by an adhesive of some sort or some kind of joint (of which there are many.) And if there are metal hinges or clasps involved, then you have to add those into the equation, too.
So a wooden box is made of all sorts of things. Why do you ask?
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Superman wears Jack Bauer pajamas.