Perturbative QCD calculations may have colored partons in the final state, but only the colorless hadrons that are ultimately produced are observed experimentally. Thus, to describe what is observed in a detector as a result of a given process, all outgoing colored partons must first undergo parton showering and then combination of the produced partons into hadrons. The terms "fragmentation" and "hadronization" are often used interchangeably in the literature to describe soft QCD radiation, formation of hadrons, or both processes together.