D2L is Michigan State University's centrally supported Learning Management System. When it was adopted in July 2012, the company called itself and its products Desire2Learn. In 2014, the company renamed its product line Brightspace. At MSU, these products include the Learning Environment, ePortfolio, and the Learning Repository. In 2015, the company changed its name from Desire2Learn to just D2L.
This causes some confusion as documentation may include any of the above naming conventions. Desire2Learn should be considered equivalent to D2L. At MSU, we have used the D2L convention in access (http://d2l.msu.edu) and finding help (http://help.d2l.msu.edu).
As D2L changes its documentation, the Brightspace name may appear. Be aware it simply refers to the D2L product line.