Hands-on projects usually involve building or creating somthing either as an individual or in a collaborative group.  All background information and instructions are provided for the students so they can direct themselves with some guidance from you.  These projects involve students in creating something useful ... in fact, activities are included that require the student to "use" what they have created.  Authentic, Hands-On, Collaborative, Self -Directed, and Engaging .  These are lessons for the 21st Century learner.