It means that the package has been signed for by FedEx and is currently in transit.
The tracking process works as follows: Fedex first receives your shipment, it scans a list of inventory items to ensure nothing was lost or compromised. Secondly, they will calculate the total weight and dimensions of the package before giving you a price quote on shipping. Once this information is gathered, they create an email with a courier order despatched notification with all the pertinent information like tracking number assigned and consignment details.