Content Delivery Network - network of servers worldwide that store copies of your content close to users. Like having product warehouses in every city for faster delivery.
Netflix uses CDN to store popular shows in servers near you, so when you click play, the video loads instantly instead of traveling from across the world.
All provide globally distributed edge locations that cache and deliver content closer to users to reduce latency and offload origin servers. AWS CloudFront and GCP Cloud CDN commonly pair with their load balancers; Azure offers both Azure CDN (classic CDN profiles) and Azure Front Door (global edge entry with CDN + L7 routing/WAF); OCI CDN integrates with OCI services and partners to accelerate delivery.