Difference between Trackback and Referral links in SEO?

[sadianisar]

What is the difference between Trackback and Referral links in SEO?

[sinelogixweb]

A referral can be a link that isn't from the crawlable web, i.e., a link in an email, from facebook or some other social network which the search engines can not index, from a mobile app, from a link in a spreadsheet, pdf etc.

Trackback is a means of notifying a website that another website has linked to it. By linking to a trackback link, a webmaster can automatically inform the other website that he has added a link to one of site's pages.