Once you've created your HTML document, you need to "post" it to your Web server to make it available on the World Wide Web. Posting is nothing more than uploading or copying the documents onto the Web server. Authoring tools like the one that comes with Netscape Navigator provide "one-button publishing," meaning you can post your entire site to an ISP's server with the click of a button. If this is not available, you can use FTP to post your site. Your ISP will provide instructions.
If you have your own Web server, posting your site simply involves copying the files over to the server machine. Your URL is formed from the path to the files relative to the server's root directory. Your Web server software will provide instructions.