Shared transfer
A pre-booked transfer where you ride alongside other unrelated passengers heading to nearby destinations.
A shared transfer (sometimes called a "shuttle") consolidates multiple bookings going in the same direction into one vehicle. The per-head price is cheaper than a private transfer, but you wait for the shuttle to fill, ride along while it drops other passengers, and have less control over timing.
Shared transfers make sense for solo travellers on flexible schedules with central drop-offs. They rarely beat a private transfer when there are 3+ in your party, when you have an early flight, or when your hotel is off the main routes.