2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/39759We discuss recent progress and open questions in QCD jet physics, with particular emphasis on two areas: jet definitions and jet substructure.13 pages, 18 figures, talks given at XXXVth Rencontres de Moriond, QCD and Hadronic Interactions, Les Arcs 1800, France, March 18th-25th 2000, and DIS 2000, 8th International Workshop on Deep-Inelastic Scattering, Liverpool, UK, April 25th-30th 2000High Energy Physics - Phenomenologytext