A trackback is one of four types of linkback methods for website authors to request notification when somebody links to one of their documents.
Example: If I’m writing about a subject, and I find an article that I think makes a bunch of good points about the issue, I can link to their page as usual. But if both my site and the owner of the linked site are trackback-enabled, then my link automatically creates a notification that will inform the linked site of the new connection. This notification also provides links back and forth between the two pages, allowing readers to easily follow related streams of information
About The Word
Trackbacks have been in use since 2002, and there are currently efforts to make it’s usage an internet standard through the IETF. Though trackbacks can be very helpful, many bloggers have stopped using them. This is mostly due to some companies who have abused the feature, linking to spam sites. Though spam filters exist, the headache of having to sift through spam has led to a decline of trackback usage. On WordPress, trackbacks must be created manually, this process is explained by the first “More Information” link below.
Here’s what a trackback looks like on a site: