An RN is a license, and a BSN is a degree. To become a licensed RN, the first step is to enroll in a pre-licensure nursing program. Some programs lead to an associate’s degree (ADN) and some to a bachelor’s degree BSN). An Associate’s Degree in Nursing (ADN) can be obtained in about two years, while a BSN often requires three or four years of study. This is because a BSN equips nurses with the tools and experience necessary to advance their careers.