You can view the actual underlying HTML text of any page displayed in your browser. For example, by selecting View and then Source from the Internet Explorer menu, the HTML text for the page appears. An HTML document can be composed using a plain text editor such as Notepad. As mentioned above, a tag is a portion of the document set off from the rest of the document by angle brackets, . Tags contain information for the browser which indicate the text font, the beginning of a paragraph, a hypertext link, an image, etc.
Some tags come in pairs.
That is, they have an opening tag and a closing tag. The opening tag turns on a feature specified by a tag and the closing tag turns the feature off. For example, starts an unordered list and ends the list. Everything in between the opening tag and the closing tag is referred to as the content of the tag. The content of one tag can also include tags.