Several principles are key to assuring that the Web becomes ever more valuable. The primary design principle underlying the Web’s usefulness and growth is universality. When you make a link, you can link to anything. That means people must be able to put anything on the Web, no matter what computer they have, software they use or human language they speak and regardless of whether they have a wired or wireless Internet connection. The Web should be usable by people with disabilities. It must work with any form of information, be it a document or a point of data, and information of any quality—from a silly tweet to a scholarly paper. And it should be accessible from any kind of hardware that can connect to the Internet: stationary or mobile, small screen or large.
Allowing any site to link to any other site is necessary but not sufficient for a robust Web. The basic Web technologies that individuals and companies need to develop powerful services must be available for free, with no royalties. Amazon.com, for example, grew into a huge online bookstore, then music store, then store for all kinds of goods because it had open, free access to the technical standards on which the Web operates. Amazon, like any other Web user, could use HTML, URI and HTTP without asking anyone’s permission and without having to pay. It could also use improvements to those standards developed by the World Wide Web Consortium, allowing customers to fill out a virtual order form, pay online, rate the goods they had purchased, and so on.
Keeping the web universal and keeping its standards open help people invent new services. But a third principle—the separation of layers—partitions the design of the Web from that of the Internet.
This separation is fundamental. The Web is an application that runs on the Internet, which is an electronic network that transmits packets of information among millions of computers according to a few open protocols. An analogy is that the Web is like a household appliance that runs on the electricity network. A refrigerator or printer can function as long as it uses a few standard protocols—in the U.S., things like operating at 120 volts and 60 hertz. Similarly, any application—among them the Web, e-mail or instant messaging—can run on the Internet as long as it uses a few standard Internet protocols, such as TCP and IP.