What is the difference between a laser pointer and a laser diode module?

The major difference stems from the fact that laser pointers are meant for a consumer market and laser diodes are meant for an industrial/technical market. Laser pointers are designed to be low cost and are manufactured in high volume. Factors such as lifetime, beam quality, and ruggedness of design are not primary considerations in the design of a laser pointer. Diode modules are meant for more demanding applications and are designed and toleranced for better beam quality, longer lifetimes, and more rugged packaging. Laser pointers are meant for short periods of use, while a laser diode module can be operated for longer periods of time. Thus, laser diode modules are preferred if the size of the spot, the quality of the spot, divergence of the beam, pointing stability, or lifetime of the unit is important.