Final answer:
A person who sells and rents out buildings and houses for clients is commonly referred to as a real estate agent.
Step-by-step explanation:
A person who sells and rents out buildings and houses for clients is commonly referred to as a real estate agent. They help clients buy, sell, and rent properties, whether it's residential, commercial, or industrial. Real estate agents play a crucial role in the real estate industry by facilitating transactions between buyers and sellers.