HTML stands for Hypertext Markup Language. It's the "language" of the World Wide Web. You won't need anything special to work with HTML, just a computer, a basic text editor, and a web browser.
URL stands for uniform resource locator; it's the address of a document. For example, the URL of my website, PixelScripts, is http://pixelscripts.diaryland.com.
You do not need to have a connection to the Internet in order to view your web page, just a web browser such as Internet Explorer. Almost all computers come with Internet Explorer automatically installed.
Before you begin learning HTML, I strongly recommend you become familiar with computers in general, especially your own. You need to learn how to operate your computer efficiently and should be comfortable with doing things such as installing software, organizing files and folders, using the control panel, and exploring the files located in your computer. No, you do not need to know how to do these things to learn HTML, but if you can, it would greatly simplify the process.
When you save your HTML documents, you have to save them as whatever_file_name.html. Always remember the .html part. Stick to lowercase letters, and don't use spaces. If you have to have a space, use an underscore: _.
If you are using notepad, and you save a file with the .html extension, but notepad still saves it as a .txt file (ex.: index.html.txt), simply type your filename like this: "filename.html". Using the quotations will tell notepad not to use the default .txt extension.
Make sure you save your HTML files in standard (ASCII) text format, otherwise they will not work. If you are using Notepad, then this should not be a problem.
Your main page must be saved as index.html. This is the first page your visitors will see when they try to access your website.
Note, however that some host require you to name your main page default.html. This is rare
Testing While You Code
While you're editing your web pages you may want to test them out as you're editing them. To do this start up your web browser, go to file > open, and navigate to the .html file that you are working on, located somewhere on your hard drive. Now, as you change things, you can save the document, and refresh your browser. It will change, and show you what the new document looks like.
If you are having problems with your browser trying to connect to the internet everytime you start it, try this:
Internet Explorer; Most Versions Open Internet Explorer, go to tools > options; click general tab, click "use blank" under homepage. (IE 4: This is on view menu instead of tools menu)
Netscape Navigator; Most Versions Start Netscape, go to edit > preferences; choose navigator category; select "blank page" under "navigator starts with".