A gamer is a person who plays interactive games, especially video games, tabletop role-playing games, and skill-based card games, and who plays for usually long periods of time. Some gamers are competitive, meaning that they compete in some games for money. There are many different gamer communities around the world.
An intern is a trainee who has signed on with an organisation for a brief period. An intern's goal is to gain work experience, occasionally some university credit, and always an overall feel for the industry they're interning in. Internships may be paid, partially paid, or unpaid.