This is an obvious, but important question, that many people don't actually know the answer to.
The Internet is a system of networked computers registered by IP addresses to access a shared frame. Millions of computers are linked to the internet.
The World Wide Web is an information space where documents, e.g. HTML DOMs, are accessible via URIs, e.g. web URLs. (URIs which, in addition to providing a specific identifier or "name" like a URI, also provide the "address" where you can locate it on a Server). The World Wide Web serves and edits these documents based on the HTTP language. The World Wide Web is built on top of the Internet - i.e. the IP connections. The HTTP language and HTML DOMs are just one of many types of languages and documents/data that can be transferred across the Internet.| Back