These are about recognizing which sites are fake in terms of "built just for SEO" or "spam" and which are real (real value, good to be linked from). CF is Citation Flow and TF is Trust Flow. Trust Flow is easy to understand - good, well known, trustworthy sites do not link to spam like "get-rich-quick" programs and similar sites; they link to other trusted sites. TF thus means how well you are linked to the other trusted sites Citation Flow is about how many backlinks does a URL have - i.e. how many sites are linking to it. However, each link has its weight, so it is not just a simple count of links, but their quality also matters. More info: http://blog.majesticseo.com/development/flow-metrics/