worker

noun:a person who performs work, especially for wages; an employee
- The factory worker assembled the car parts with great skill.
noun:a non-reproductive class in social insects, such as ants, bees, or termites, that performs tasks like finding food, caring for the young, and defending the colony
- The worker ants tirelessly gathered food for the colony.
noun:a background process or thread in computing that performs tasks independently of the main program flow
- The application uses a worker thread to handle file uploads without freezing the user interface.