Minijets:. Origin and Usefulness

As the energy is increased, minijet production provides a steadily-increasing fraction of the total cross section in hadron-hadron collisions. We argue that, rather than being a new phenomenon, this is the result of the hard tail of soft diffractive events becoming increasingly prominent. We discuss the production of multiple minijets, and point out the interest of searching for minijet events in deep inelastic lepton scattering at HERA. Consequences for charm production are considered.