Absolute links are links that can not change, they go to one place. You can also create links to other places as well such as a link to e-mail you or a link to ftp sites. Well here's a practice for you. Dissect this link to see where it goes and what its label is.
Anchors are links to certain places in a document.
This can be helpful if you want to have a table of contents for the page and then have links going to different place on your page. Making a link is a two step process. First, you need to make an anchor and then second, you need to a make a link to an anchor. Now, rename anchor name to whatever you want and you're set. Now, you need to make the link to the anchor.