The first digit of the course number signifies the level for which the course is intended.
Level 1 (i.e. 1000-series) courses are introductory, foundation, basic skill type courses, or courses generally appropriate to the first year of a full-time undergraduate programme.
Level 2 (i.e. 2000-series) courses are intermediate level courses, or courses which are generally appropriate to the second year of an undergraduate programme.
Level 3 (i.e. 3000-series) and Level 4 (i.e. 4000-series) courses are those courses which involve more advanced study skills often requiring Level 1 and Level 2 prerequisites.