10.5170/CERN-2006-002.379Herr, WernerBeam-beam interactionsCERN2006Accelerators and Storage Rings2006engCERNOne of the most severe limitations in high intensity particle colliders is the beam-beam interaction, i.e. the perturbation of the beams as they cross the opposing beam. This introduction to beam-beam effects concentrates on a description of the phenomena that are present in modern colliding beams facilities.