A set is a folder in the learning plan that contains learning assets. Although the assets within it may have a due date, the set itself does not. The General and Development plan sets can have subsets (which are more refined groupings within a set) but only one level of a subset is allowed.
You can create sets on the Personal Learning tab in your learning plan
To create a set
.
until the new set is directly below the name of the set to which you want to add it as a subset.
. The new set becomes a subset.