Amazon CloudFront is a CDN (content delivery network: a set of servers in many cities that keep copies of a site's files and serve each visitor from a nearby server) from Amazon Web Services. Viewers connect to the nearest of more than 750 points of presence; CloudFront answers from its cache or forwards the request to the origin, the server or storage that holds the original content, such as Amazon S3, a load balancer or any public URL.
It delivers static and dynamic web content, APIs (including WebSockets and gRPC), live and on-demand video and software updates. Security features include traffic encryption, access controls, AWS WAF (a web application firewall) and AWS Shield Standard against DDoS attacks at no extra charge. Small serverless functions can run at the edge to change requests and responses. Data transfer from AWS origins to CloudFront is free.
CloudFront is billed either by actual usage of each service or through flat-rate monthly plans per distribution that include a usage allowance and have no overage charges.