Anchor title
This is the title of that particular page you put the meta tag in. it does the same as keywords by helping google determine what the site is about and makes your site available to searchers looking for that particular topic. I see many sites making huge mistakes in this. Often you go to a site and you see on your browser tab "index" or "http://www.thedudessite.com". so, basically they didn't pay any attention to the anchor title and didn't put one in the meta tag. Sure the site may get popular eventually but it probably cost 4 times the advertising price or 10 times as long to get there. Basically you want to name it well and relevant to the topic of the site. For example:
If your site is about dog information and lets say you and you find a good keyword name that is what your site is about like "Dog Breed information". Now as I said before in other articles you should try to get a metatag for each page on your site, so therefore the anchor will be much different depending on what that page is about. Don't name every page the same as each other. It would be a shame to have all of those pages in your website and google only grabs 3 of them.