CloudFront
In plain terms
Amazon's content delivery network (CDN).
Going deeper
CloudFront caches and serves content from edge locations worldwide for low latency, integrating with other AWS services. It speeds global content delivery.
Under the hood
Edge caching plus Lambda@Edge for compute; integrates with S3 and shields origins from load.
Examples
Static asset delivery, video streaming, global websites, S3 acceleration.
Think of it like...
Like local distribution centers stocking popular goods near every customer.