My license was in a different state so it may vary a bit in VT. To sell a home you need a real estate sales person’s license. That license must operate under a broker. The agency you work for typically will have one or more brokers in it who acts as a coach and advisor. Some agencies will have a difference in commission split. The agencies that pay a bigger split usually require more investment from you on things like advertising your listings and buy office materials. Agencies that pay a lower split will generally provide all that for you. After 5 years experience, you can apply for a broker’s license which would be required if you wanted to start your own brokerage and leave your current one. Most realtors do not apply for brokers licenses.

Realtor is a trademarked term and refers only to real estate salespeople who are members of the National Association of Realtors. You will likely join this if you work for a traditional local brokerage. Alternative real estate sales channels like Redfin and Sold by Zillow probably don’t join NAR, though I don’t know too much about them. I haven’t practiced real estate in a while.