A friend just asked me about the difference between the nurse acronyms-- RN vs. LPN vs. BSN vs. ADN. The simple explanation is that RN and LPN are license levels, while BSN and ADN are degrees than an RN may have.
A Licensed Practical Nurse (LPN) typically has a year of career training before licensure. To generalize, LPN education focuses on caring for patients in stable condition with predictable outcomes. They can do the large majority of hands-on physical tasks (meds, IVs, catheters, wound care, etc) but they are not trained in the underlying theory. What they can't do are tasks that require assessment and independent action, like administering blood products. An LPN works under the direction of doctors and RNs.
A Registered Nurse (RN) gets a college degree before licensure. In addition to the physical tasks, they have more leadership and decision-making responsibilities. An RN does assessments, makes nursing diagnoses, provides education and counseling, and delegates care tasks to LPNs and unlicensed personnel. RNs are considered professionals in their own right; though they work with doctors in providing medical care, they act independently in providing nursing care.
The RN may have an Associate's Degree in Nursing (ADN) or Bachelor's Degree in Nursing (BSN). There's no difference in what they can do in practice, but the BSN-prepared nurse has a stronger grounding in nursing theory, pathophysiology, and assorted other science.
Of course these are just generalizations. An LPN who's been around for years will know a lot more than a brand new BSN-prepared RN, even though the LPN didn't have as many credits in school. And all nurses do a lot more than the few examples I've listed.