An individual can join the National Association of Realtors and become a “Realtor” without even holding a license to sell real estate. For instance, there are a few Realtors who are appraisers, not agents or brokers. NAR even offers professional designations for appraisers (RAA for residential appraisers and GAA for commercial appraisers).
One of the most politically active groups in the affairs of The Appraisal Foundation is NAR and its Appraiser section.
Not all agents or brokers are Realtors and not all Realtors are agents or brokers.