Forum Moderators: open
welcome to WebmasterWorld.
Anchortext is the text used in the link (normally underlined) leading towards a page. It is an important factor in that through its text it is a form of motivation towards the page it is linking to.
Google also has an advanced search function where you can specify this.
I'm not sure what you mean with link structure, but people often mean ways of linking pages with each other.
For example, a lot of links on one page (link page) of only a few on every page.
You might want to check the Google library (see the link on the top left of the page) for more information and there is also a seperate linking forum here as well.