A trainee is someone who is learning how to do a job or skill by working under the guidance of more experienced people. When you're a trainee, you're not expected to know everything yet. You're there to watch, practice, and gradually take on more responsibility as you learn.

A new firefighter might spend months as a trainee, learning how to use equipment and respond to emergencies alongside veteran firefighters. A trainee chef works in a kitchen learning techniques from the head chef. A trainee astronaut studies for years before going to space.

Being a trainee is different from being a student in a classroom: trainees learn by actually doing the work, even if they make mistakes along the way. A trainee cashier practices scanning items and making change with real customers. A trainee pilot flies actual planes, with an instructor right there in the cockpit.

Most people are trainees at some point when starting something new and challenging. The trainee period is when you're allowed to ask questions, move slowly, and figure things out. Once you've mastered the skills, you're no longer a trainee: you're a full professional, and maybe someday you'll train trainees yourself.