A Unit of Competency is a specification of a set of standards of performance required as defined in a training package (Reference: Standards for RTOs (2015), Page 13). Simply put, a UOC can be thought of as a “subject” or “single course” within a full qualification.
UOCs typically have a three-letter designator which represents the area of training. For example, the Aeroskills designator is ‘MEA’.
See the FAQ What is an MEA?