HTML tags are added to documents published on the Web. The documents are retrieved using a Web client program that displays them in accordance with the tags. (Web clients are often referred to as Web browsers).
The tags are separated from the text of the document by the "<" and ">" symbols. Many, though not all, tags have a beginning and end, <tag> ... </tag>.
You can create HTML documents with Notepad or any other text editor, but be sure to save it as an ASCII file with the extension .htm or .html. Do not accidently save it with the extension .txt and do not accidently save it as a .doc or other type of word processing file.
Once you save an HTML document, you can view it using Firefox, Microsoft Internet Explorer, Apple Safari or any other Web client using the file -> open command. (In practice, there are differences among Web client programs, but the basic HTML tags are well standardized and all clients interpret them the same way).
You can also use the client's the view -> source command to see the HTML file for pages you find on the Web. That is a good way to learn about new HTML tags. (You can start by viewing the source file for this document).
The following are a few HTML tags to get you started with document mark up:
Document Structure
<html>..</html> bracket the entire document
<head>..</head> bracket the heading section
<body>..</body> bracket the body section
Head element
<title>..</title> title, within head section
Headings and paragraphs
<p> .. </p> paragraph
<h1>..</h1> level 1 heading
<h2>..</h2> level 2 heading
...
<h7>..</h7> level 7 heading
<hr> horizontal rule
<br> force a line break
Character style
<b>..</b> boldface type
<i>..</i> italic type
<tt>..</tt> monospace, typewriter-style type
<u>..</u> underline type