Moz Page Authority is Moz’s attempt to score how well a page of a website will rank on search engine results. This is provided on an exponential scale between 0 and 100.
Majestic Trust Flow is a score based on how many links a domain gets from a set of trusted seed sites. It can be calculated page wise as well as domain wise, where Page Authority can be calculated only web page wise. This value is provided on a linear scale between 0 and 100.