  We review the basic concepts of all-order calculations in Quantum
Chromodynamics (QCD) and their application to collider phenomenology. We start
by discussing the factorization properties of QCD amplitudes and cross-sections
in the soft and collinear limits and their resulting all-order exponentiation.
We then discuss several applications of this formalism to observables which are
of great interest at particle colliders. In this context, we describe the
all-order resummation of event-shape distributions, as well as observables that
probe the internal structure of hadronic jets.
