Difference between Web2.0 and Contextual Link?

I've been out of this way too long, and I'm trying to get back into it. When I looked on here for the kind of backlinks that are working, "contextual" kept coming up. I'm not quite sure what that is. It sounds very similar to web2.0 backlinks, where you have a site or a blog with a link back to your site. Are they related, or are there some distinct differences that I should be aware of if I want to start backlinking to my sites again?Thanks.

Contextual links means in-content links be it on web2.0 or article sites or guest posts etc.