The World Wide Web, also known as the W.W.W. or just "the Web", is a collection of connected multimedia documents — known collectively as "web pages" — that is accessed over the Internet. These "multimedia documents" could be written information, pictures, animations, sounds, videos, games, and more, or a combination of any of these! The other neat thing about the World Wide Web is that many of these documents have parts that connect you to other documents, so you can move between pieces of related information.
If it helps, think of the World Wide Web as a giant library. When you open a book in this library, you may just see written text, or you may see a photograph or drawing. You may even hear a sound or see an animation or video, or you may even be able to play a game! Plus, there are certain words in the book that reference a different part of the book, or another book entirely! That's kind of how the World Wide Web works.
Internet vs. World Wide Web
There are many people who use the term "Internet" as a sort of catch-all term that covers the World Wide Web as well. We do it here at Techboomers, too, mostly to avoid confusion from people who aren't aware that there is a difference between the Internet and the World Wide Web. The two ARE different, though, and we'll explain how.
As we explained in our What is the Internet article, the Internet is a collection of computers and computer networks that are connected together, in order to facilitate sending information back and forth between them. The World Wide Web is simply a collection of information (albeit a very big one!) that takes advantage of the Internet and its connections in order to make itself accessible to many different people all at the same time.
If it helps, think of it in terms of trade. In addition to taking advantage of natural air and water currents (for airplanes and boats), people have built roads, bridges, railways, canals, tunnels, and all manner of transportation aids all over the world in order to help people get from one place to another. You can think of this collection of transportation connections as the Internet. Now, one of the things that this transportation network has made possible is the moving of goods from one part of the world to another. This is why, at your local supermarket, you can find bananas from South America, pasta from Europe, and electronics from East Asia. In this sense, you can think of all of these products moving back and forth across a worldwide transportation network as the World Wide Web, and your supermarket as a website where many of these connections come together.
The main point to remember is that the World Wide Web is to the Internet what trade goods are to transportation routes: it's a service or resource that is made possible or available by the underlying connections. The World Wide Web needs the Internet to work, but the Internet doesn't need the World Wide Web to work. Likewise, there are some computer programs, such as the communication service Skype, that use the Internet to work, but don't necessarily use the World Wide Web all that much.
Who invented the World Wide Web?
Credit for the invention of the World Wide Web most often goes to British computer scientist Timothy Berners-Lee, who created it while he was working at the European Organization for Nuclear Research (C.E.R.N.) in Switzerland during the late 1980s and early 1990s. However, Berners-Lee's research was based on ideas about new ways to share information using computing technology, which date as far back as the 1940s. These include Vannevar Bush's idea for a filing system that could mimic how the human brain works (which he called a "Memex"), Ted Nelson's conception of "hypertext" as the multi-directional connection scheme that such a system would be based on, and Douglas Engelbart's "online system" that would provide an easy-to-use computer network and interface (i.e. a personal computer) that could put this into practice.
Berners-Lee took these ideas on how to connect libraries of documents and built a user-friendly system for doing so on top of the already-existing infrastructure of the Internet. Thus, the World Wide Web as we know it was born.