As one familiar with the word "assembly" might assume, assemblage is a form of sculpture comprised of "found" objects arranged in such a way that they create a piece. These objects can be anything organic or man-made. Scraps of wood, stones, old shoes, baked bean cans and a discarded baby buggy - or any of the other 84,000,000 items not here mentioned by name - all qualify for inclusion in an assemblage. Whatever catches the artist's eye, and fits properly in the composition to make a unified whole, is fair game.
The important thing to know about assemblage is that it is "supposed" to be three-dimensional and different from collage, which is "supposed" to be two-dimensional (though both are similarly eclectic in nature and composition). But! There's a really fine, nearly invisible line between between a bulky, multi-layered collage and an assemblage done in extremely shallow relief. In this large, grey area between assemb- and col-, the safest course is to take the artist's word for it.
Also Known As: construction, bricolage, collage (inaccurately), sculpture