A training can be interactive or completed solely by the user. For example, staff can take a training through a Learning Management System (LMS).
You can assess competency by administering a quiz after the quiz to see if the staff member’s knowledge is sufficient (think C level proficiency), but you will need to ensure that you are ‘testing’ for a comprehensive understanding of the topic.
A competency is administered by someone with experience and assesses the skills of a staff member. A competency should be an interactive event.
Remember that all of the above should be documented, and a part of the employee’s Human Resources (HR) file.