2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/153242The high energy physics advantages, disadvantages and luminosity requirements of hadrons, of leptons and photon-photon colliders are considered. Technical arguments for increased energy in each type of machine are presented. Their relative size, and the implications of size on cost are discussed.LaTeX, 10 pages, 10figuresAccelerator Physicstext