Understanding Physics is designed to work with learning strategies such as microcomputer-based labs and interactive lectures that ate increasingly being used in physics instruction. In doing so, it incorporates new approaches based upon Physics Education Research (PER), aligns with courses that use computer-based laboratory tools, and supports Activity-Based Physics in lectures, labs, and recitations. A set of related materials collectively known as The Physics Suite is available to support active learning in both the lecture and the lab.