Скачать или смотреть Quick comparison of S3 hosted file vs. CloudFront hosted file

I didn't cover this in the video, but suppose you are hosting your bucket in an African region. If a U.S. browser were to hit your S3 endpoint, there will be a considerable lag between the time the request is made and the response is returned. After all, the request has to travel around the world.

With your asset behind a CloudFront URI, a U.S. request would hit one of the edge servers nearest to the location of the browser making the request, and would receive a cached copy of the file. (Technically, if the file wasn't present, it would be retrieved from Africa the first time, but would then remain and the Edge server would serve the cached version for any subsequent request, or until TIL has expired.)

All of that to say, CloudFront is Amazon's approach to providing CDNs. If your site is popular enough to handle lots of requests, particularly from a large, potentially world-wide geographical area, having a network of caches in place probably makes sense for you.