The expression "warp and weft" (also "warp and woof" and "woof and warp") is used metaphorically the way "fabric" is (e.g., "the warp and the weft of a student's life" equates to "the fabric of a student's life"). Warp and weft are also used more generally to describe the basic dichotomy of the world we live in: up/down, in/out, yin/yang, and so on. This term is also used to denote the underlying structure upon which something is built.