They've got a lot in common, but mortar and cement aren't interchangeable. Get the inside track on the difference in this Pro Tips blog.
Unit 2 CM Lime, Cement, Aggregates, Mortor, PDF
Fast-Setting Concrete Mix
Concrete vs. Cement vs. Mortar, Ask Kevin
Differences Between Cement, Concrete and Mortar - Builders
Building Construction Material (Mortars And Plasters) - PowerPoint
Sand Mix
Multi-Purpose Sand
The Difference Between Mortar and Cement
How to Choose the Right Mortar Mix Type: N, O, S, or M