The word staff has two main meanings:

1. A group of people who work together for an organization. A school has a staff that includes teachers, administrators, custodians, and cafeteria workers. A hospital staff includes doctors, nurses, and many other professionals. When you hear that a business is “fully staffed,” it means they have all the workers they need. The word suggests people working as a team toward common goals, like a restaurant staff working together during a busy dinner service.
2. A long stick or pole, often used for support or as a symbol of authority. Shepherds carried staffs to help them walk across rough terrain and guide their sheep. In ancient times, rulers held ornate staffs to show their power. Wizards in fantasy stories often carry magical staffs. Hikers today use walking staffs (or walking sticks) to maintain balance on trails.

In music, the lines on which notes are written form what's called a staff.