Binary oppositions are any one of the series of oppositions through which humans differentiate objects and create meaning? One of the terms is priveledged over the other yet dependent upon its exclusion in order to assert its dominance. The work of deconstruction is to digest these terms and destablize the particles that hold the priveledged term together.
Examples: White/Black (skin) Man/Woman (genitals) Hetero/Homo (genitals/anus). The priviledged term often overcodes desire and provides an outlet that upholds society's relations of force.