Final answer:
Hyperlinks are the fundamental element connecting documents on the Web, implemented by Tim Berners-Lee during the early development of the internet. While IP addresses, domain names, and URLs are critical to the web, hyperlinks specifically enable the interlinking of countless web pages.
Step-by-step explanation:
The fundamental element connecting documents on the Web is hyperlinks. When Tim Berners-Lee, the inventor of the World Wide Web, developed the early web using a NeXT computer, he created a system based on HTML and URLs to format and link documents across servers. Hyperlinks are the clickable portions of a web document that take you to another location on the web, be it on the same page, a different page on the same website, or a different website altogether.
While Ted Nelson envisioned a system of interconnected documents through bi-directional links, his concept was never fully realized, and instead, Berners-Lee's implementation of unidirectional hyperlinks became the standard for the burgeoning internet.
Although IP addresses, domain names, and URLs are essential components of the web infrastructure, it is the hyperlink that is the fundamental connective tissue allowing billions of web documents to link to one another, forming an interconnected network of information.