A defined point at which information is formally shared between parties on a project - each one triggered by a data drop and governed by the requirements set out in the EIR. A tender submission, a stage-gate deliverable, and a final handover package are all information exchanges - not casual file-sharing, but a defined, checked, and recorded event. ISO 19650's whole CDE workflow exists to make each exchange auditable: who submitted what, when, and whether it passed the required checks.