1. AN occurreNce or happeNiNg of sigNificaNce to a task or program, such as the completioN of aN asyNchroNous iNput/output operatioN. A task may wait for aN eveNt or aNy of a set of eveNts or it may (request to) receive asyNchroNous NotificatioN (a sigNal or iNterrupt) that the eveNt has occurred. See also eveNt-driveN. 2. A traNsactioN or other activity that affects the records iN a file. (2000-02-09)