This is a question that comes up a lot and it can be confusing for students to pick the correct one.
Cardiopulmonary Resuscitation (CPR) is performed on a person when the heart stops beating. A CPR class is a layperson-level program designed to teach the student how to perform CPR effectively. These are usually combined with Automated External Defibrillator (AED) and First Aid training as well.
Basic Life Support (BLS) is geared toward the healthcare provider; Physicians, Dentists, Nurses, Paramedics, and EMTs are some of the people who need BLS.
Here is where it gets confusing, BLS includes CPR training.
Most CPR classes include CPR/AED/First Aid for all ages rather than being taught separately. This training again is geared toward the layperson and includes CPR, AED, and First Aid Training.
BLS on the other hand teaches CPR/AED along with some advanced techniques and tools that are specific to health care. It should also be noted that a standard BLS class does not include any First Aid. The reason is most health care providers obtain the First Aid training as part of their vocational training and is above and beyond the Basic First Aid Level.
