What is "trapping"?

A graphic design technique aimed at minimizing the effect of misregistration. Misregistration, or the misalignment of colors, can happen in full-color process printing. To avoid it, trapping can be done in two different ways: 1. By a "spread" in which a lighter object slightly overlaps a dark background, or 2. By a "choke" in which a lighter background overlaps a darker object.