What is Amazon CloudFront? A plain-English explainer
Amazon CloudFront is AWS’s content delivery network, or CDN — a service that caches copies of your content at edge locations physically closer to your users, so it loads faster than fetching it from a single origin server every time. Without a CDN, every request travels all the way back to wherever your application is actually hosted, and users far from that location feel the extra distance as lag. CloudFront sits in front of that origin, serving cached copies from a nearby edge location whenever it can, and only reaching back to the origin when it genuinely needs to. Here is what a CDN does more generally, what CloudFront specifically adds, where it fits alongside the rest of AWS, and how it shows up in certification study.
What a CDN actually does
A content delivery network is a geographically distributed set of servers that cache and serve content from locations near the people requesting it, instead of every request travelling to one central origin. Our what-is-a-content-delivery-network explainer covers the concept in more depth; the short version is that distance and network hops both add latency, and a CDN shortens that path by keeping copies close to where they will be read.
CloudFront is AWS’s own CDN, built on Amazon’s global network of edge locations and tightly integrated with the rest of AWS — particularly S3, EC2 and Elastic Load Balancing as origins.
What CloudFront does
CloudFront caches content — files, images, video, whole pages, even dynamic API responses in some configurations — at edge locations around the world. When a user requests something, CloudFront routes the request to a nearby edge location; if that content is already cached there, it is served immediately without touching the origin at all.
That caching has two effects at once: users get faster responses because the content is physically closer, and the origin server sees far less direct traffic because CloudFront is absorbing the repeat requests. CloudFront also carries protections at the edge — filtering and absorbing certain types of traffic spikes and malicious requests before they ever reach the origin, which is part of why it is often placed in front of applications for security reasons as well as speed.
Common uses
CloudFront is commonly used to serve static assets such as images, stylesheets and JavaScript files, to deliver video and other media efficiently, to speed up entire websites by caching whole pages at the edge, and to sit in front of APIs to reduce latency and shield backends from direct traffic. It works whether the origin is an S3 bucket holding static files or a full application running on EC2 or behind a load balancer.
- Static assets — images, CSS, JavaScript, downloadable files
- Media delivery — video and audio streaming
- Whole websites — caching pages at the edge for faster load times
- APIs — reducing latency and absorbing traffic in front of a backend
How CloudFront fits alongside other CDNs
CloudFront is AWS’s CDN, and the other major clouds each offer their own counterpart: Azure Front Door and Azure CDN on Microsoft Azure, and Google Cloud CDN on Google Cloud Platform. All three do fundamentally the same job — caching content at edge locations close to users — and the choice mostly comes down to which cloud the rest of the application already lives in, since a CDN integrates most easily with an origin on the same platform.
CloudFront can technically front an origin outside AWS, but it is most naturally used with an AWS-hosted origin, which is why it is usually discussed as part of an AWS architecture rather than as a standalone product.
When you would use CloudFront
CloudFront makes sense whenever an application has users spread across different locations and would benefit from faster load times, or whenever an origin needs to be shielded from a high volume of repeat requests. It is a natural fit for anything already running on AWS — a static site on S3, a dynamic application on EC2, or an API — where adding a CDN in front is a comparatively small configuration change for a meaningful improvement in speed and resilience.
CloudFront and pricing
Like most AWS services, CloudFront is pay-for-use — you are charged based on the data transferred and requests served, rather than a fixed subscription. Exact rates and any free-tier allowances change over time, so check the AWS pricing page for current figures rather than relying on a fixed number here.
Where CloudFront appears in certification study
CloudFront comes up across AWS certifications as one of the standard building blocks of a well-architected application: the AWS Cloud Practitioner exam expects a basic definition and purpose, while the Solutions Architect Associate and Developer Associate exams go further into when to use it, how it pairs with S3 and other origins, and how it fits into a broader architecture for performance and availability.
This article deliberately stays at that introductory level. How CloudFront distributions are actually configured, cached, and tuned is exam-depth material, and that is what our /revision study library is built to cover.
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