A coworker is someone who works at the same company as you. Imagine that your school has lots of classrooms, just like a big company has lots of offices. All the people who work in those offices, like your teacher and the principal, are your coworkers. You might work on a team with your coworkers or talk to them a lot during the day. It's important to be friendly and respectful to your coworkers because you all need to work together to make the company run smoothly.