Divisions are specific to the Canadian CMS and NMS content only.
Divisions are used to arrange similar content.
For example, waterproofing elements are classified in Division 07 and electrical elements are classified in Division 26.
Assigning content into Divisions allows you to more quickly find their interests. For example, a bidder looking into a tender document that is interested in whether the project has foundation waterproofing in the scope of work will turn to Division 07 of the document for review. Similarly, the electrical contractor would turn to Div 26.
Divisions make it easier for a specifier to retrieve information in their own library.
"Division" may translate to discipline or trade in a broader sense of the definition.