What is the difference between an account and a company?

What is the difference between an account and a company?

I am in the field of commercial real estate, and trying to add brokers/landlords in as contacts. But by doing that it wants to make them and "account" and not a "company". I was thinking accounts were my clients. These are definitely not leads.

Any advice on how to organize? Is there a way to add a "Company" field under contacts.