Trackbacks,in a layman’s language are a way to notify a website when you publish something and that you’ve linked to them. When you send a trackback, a link with a short excerpt(often seen as a “teaser”) of your post will appear on the referred website. Trackback is more prone to SPAM.
Pingbacks were designed to solve some of the problems that people saw with trackbacks. Both Pingbacks and trackbacks use different technologies,XML-RPC and HTTP POST, respectively to post the content.
Pingbacks do not send any content. A pingback works automatically when a person A shares a link about some post from a person B’s blog on his website.
Quite similar to Trackbacks and Pingbacks a Refback,is whenever a browser traverses an incoming link from Site A (originator) to Site B (receptor) the browser will send a referer value indicating the URL from where the user came. Site B might publish a link to Site A after visiting Site A and extracting relevant information from Site A such as the title, meta information, the link text, and so on.