Temporarily shifting workloads from private cloud to public cloud during peak demand periods. Like a restaurant opening an outdoor patio when they're too busy to handle customers inside.
An e-commerce site runs on its private servers normally, but automatically bursts to AWS during Black Friday to handle the massive traffic spike.
Cloud bursting is an architecture pattern (not a single managed service). It’s typically implemented by combining hybrid connectivity (VPN/direct links), identity, networking, automation/orchestration, and elastic compute services so workloads can expand from a private environment into a public cloud during demand spikes.