a standard to automatically create links between webpages…
Trackback is a standard that can be used to automatically create a link between webpages (reciprocal link), usually between webpages on different websites. A trackback-based system may be used to push content to an external website or create a topic-portal.
To use trackbacks, both the author and respondent must use a technology that implements the standard, such as online journal (blog) publishing software.
When displayed under a blog entry, clicking a ‘Trackback’ link will show a list of webpages that have linked to that entry (perhaps more clearly labelled: ‘Links to this entry ’, ‘Pages linking to this entry’ or ‘Remote comments’).
…[a local] comment cannot be retracted or edited.
Online journal publishing software (used to create blogs), can include a feature that enables readers to add their views/opinions of an entry (post) as a comment. Comments are usually listed under the entry in order of reply. Aside from requiring the respondent to have an active email address, any reader may add a comment to a blog entry.
The respondent typically cannot retract or edit a comment submitted to the author’s website.
…enables the respondent to maintain ownership and control over content they have created…
Readers may create their own blog entry in response to the original post. Rather than add a comment to the author’s post and create their own blog entry, they can use the trackback standard to link the two posts (made significantly easier if their publishing software is trackback enabled). When the respondent’s blog entry is published, the software notifies (pings) the author’s publishing software. A link and excerpt of the respondent’s post are then automatically added to the author’s post.
If the respondent revises their post at a later date, for example to correct a spelling mistake, the author's entry is automatically re-notified and the respondent’s excerpt ‘corrected’. The benefit of this use of the trackback standard is that respondents maintain ownership and control over content they have created and contribute to the larger discussion.
As entries are published … they are automatically added to the directory.
The trackback standard can also be used to create a content directory, for example act as a portal to blog entries on a specific topic. The directory webpage ‘declares’ itself a hub for a particular topic and links to related blog entries as they are published. This application of the trackback standard has much in common with Really Simple Syndication (RSS), a method of providing virtual news-feeds.