From Qedoc

Learning modules are divided into levels (version 1) or activities (from version 2).

A level/activity is a quiz-within-a-quiz. In other words, each Qedoc learning module presents one or more levels to the learner. Each level is a self-contained quiz. A level can consist of a randomised collection of questions, so it may contain different questions each time it is played through.

Scoring and tracking of results is done on a level-basis, so that the overall results for any module can be broken down by level.

From version 2, the term "activity" is used, and encompasses the greater range of interactive learning methods available (i.e. more than just quizzes).