HTTP is a protocol which allows the fetching of resources, such as HTML documents. A complete document is reconstructed from the different sub-documents fetched, for instance text, layout description, images, videos, scripts, and more.
- caching (the cache can be public or private, like the browser cache)
- filtering (like an antivirus scan, parental controls, …)
- load balancing (to allow multiple servers to serve the different requests)
- authentication (to control access to different resources)
