What does "Trust Factor " mean?

Trust Factor :

Google's Trust Factor is arrived at by Google factoring in many things they can determine about a website, to assign their overall arbitrary value of how trustworthy the website is. The higher the Trust Factor (so Google says) the more likely pages from that site will rank well at Google. Some of the known Trust Factors are: Having a security certificate, a privacy policy, terms and conditions, updating the site regularly, having longer articles, monitoring your outbound links, having inbound links from reputable sites, social media mentions, how long people stay on your website, and many others.

 What is the Trust Factor?