The system needed to be robust so that if one computer went down it wouldn't take any of the others offline. Once connected, the computers needed a way to communicate. Since then, the Internet has grown nearly exponentially. In the early 1980's, the Internet had but 213 registered hosts. By January 1995, there were 4.85 million registered hosts.
Hosts are the servers that make up the Internet.
Services such as Web pages, FTP sites, newsgroups, e-mail, Gopher sites, etc., are all individual functions of these servers. These protocols also allow the linking of one document to another, making the Web a vast collection of interconnected documents, spanning the world. A web site is a collection of web pages, which can be read by a web browser. Essentially, you need a computer, an Internet connection, and a web browser. Most workplaces today, including those of our NASA clients, have built-in Internet connections.