Cross-cloud describes security tools, controls, or policies that work across multiple public cloud providers, such as AWS, Azure, and GCP. It is often used for prevention, access control, networking, or policy enforcement that must remain consistent even when workloads move between clouds.
This matters because attackers do not care which provider hosts a target; they look for the weakest configuration, identity, or network path across the whole environment. A cross-cloud control can reduce that gap by applying the same baseline rules, segmentation, or access checks everywhere. In defense, the term usually appears when teams want one policy model or one control plane to cover several clouds, but it does not automatically mean full posture visibility, runtime protection, or CNAPP-style coverage. The key question is which layer the tool actually controls.