A doorman is a friendly person that makes sure that people who enter or leave a building are doing it safely and without causing any harm. The doorman is like a security guard, but instead of watching cameras and alarms, they stand in the entrance of places like hotels or apartment buildings and greet people as they come and go.
The doorman can also help carry packages or hold the door for someone that has their hands full. They always wear fancy uniforms that help them look important and approachable. Think of a doorman like a friendly neighborhood helper, who always has a smile and a wave for you!