Shipment Tracking Glossary

Real-time GPS tracking

Continuous location of a shipment from a GPS device that fixes its own position and reports it over a cellular link on a timer — so you see where it is, not just where it was last scanned. See real-time tracking vs. carrier updates.

Scan event

A status a carrier generates when a barcode is read at a hub or facility ("departed," "arrived"). Scan events are periodic snapshots hours apart, not continuous location — the gaps between them are where visibility is lost.

Store-and-forward

A tracker logging every position on-device when there's no signal and uploading the buffered fixes once coverage returns. It's what keeps the trail complete through dead zones like rural routes or an aircraft hold.

Geofence

A virtual boundary around a place. Crossing it can trigger an alert — for example, arrival at a destination or a shipment leaving its expected route.

Chain of custody

A documented, timestamped record of where a shipment traveled and who handled it. A continuous GPS track is a strong form of chain-of-custody evidence — useful for insurance, loans, and disputes. Matters most for fine art and antiques.

Dwell time

How long a shipment sits stationary rather than moving. Unusual dwell — an 18-hour stop at an unscheduled location — is often the first sign something's wrong.

Cargo theft (strategic vs. straight)

Straight theft is physically taking a truck, trailer, or load. Strategic theft uses fraud — identity misuse, double-brokering, fake pickups — to get freight handed over willingly. See how to prevent cargo theft.

Track-and-trace

Umbrella term for following a shipment's progress. Carrier track-and-trace relies on scan events; independent GPS track-and-trace relies on the shipment reporting its own position.

LTL vs. FTL

LTL (less-than-truckload) shares a trailer across multiple shippers with several stops and hand-offs; FTL (full truckload) is one shipper's freight the whole way. LTL's extra hand-offs are exactly where carrier visibility fragments and an independent tracker helps most.

Data logger vs. real-time tracker

A data logger records conditions or location and you read it after delivery — useful for post-mortems, useless in the moment. A real-time tracker reports as it goes, so you can act during transit. See AirTags vs. real GPS for a related comparison.

Heartbeat / check-in

A periodic "I'm alive" signal from a tracker, independent of location updates. A missed heartbeat is how you learn a unit has gone dark — dead battery, out of coverage, or tampered with.

Coverage gap / dead zone

An area with no cellular signal where a tracker can't upload. Store-and-forward is what bridges it: the device keeps logging and syncs everything once it's back in range.