Supply chain visibility is the real-time tracking and monitoring of goods from supplier through distribution to customer. It combines data sources (IoT sensors, carrier APIs, warehouse systems, customs data) into a unified dashboard that shows where everything is, when it will arrive, and if there are problems. Instead of waiting for status updates from suppliers (which may be weekly or manual), visibility systems provide minute-by-minute tracking. If a container sits in port longer than expected, you know immediately and can adjust.