Browsers, like Netscape or Internet Explorer, are applications used to recognize these pages. Advanced functions of the web (VRML, Dynamic HTML, Java and multimedia) are largely developed independently, and it is the browsers job to keep up.
In order to 'be on the web', you also need to have a server, a computer that is registered on the Internet, and is always connected. While most individuals let ISPs, Internet Service Providers, host their web site, anyone with a computer and a connection can be their own server. (more on this later)