Tadbir,
MozTrust is Moz's global link trust score. It is similar to MozRank, but rather than measuring link popularity, it measures link trust. Receiving links from sources with inherent trust—such as the homepages of major university websites or certain government web pages—is a strong trust endorsement.
The help page on MozTrust is over here: http://moz.com/learn/seo/moztrust.