In the second tag, there is a slash. This tells the browser to stop doing whatever the last tag told it to do. This is always the first thing in the web document. Next is the body tag. Inside this tag you put what you want your text color, link color, background color, and background picture to be.
Relative location is discussed later.
This tells the browser that there is a picture to be inserted here. This is what is called a hyperlink or just link. When you put your mouse over this text, it will turn into a pointing finger and you will be able to click on it. When clicked, your browser will bring up the page that is refered to in the link. This tells the browser to center whatever is between the two tags.