Master tracking in FedEx refers to a tracking system used when multiple packages are shipped as part of the same order or shipment. Instead of tracking each package separately, FedEx tracking assigns a master tracking number that links all the packages together.

This master tracking number provides an overview of the entire shipment’s progress, showing details like the origin, current location, and estimated delivery date for all the packages. It's a convenient way to monitor bulk shipments without needing to track each package individually.