Trackbacks: a method of being notified when another blog links to one of your blog posts. Trackbacks require a software and/or server element in order to generate the notification. The use of trackbacks has also been called "remote commenting" since the blogger linking to your blog doesn't go to your post to leave a comment.
By using trackbacks, a blog author can track who is linking to and referencing their posts. Why is this important? Not only is it a method of expanding your readership (since the linking site provides a link to your post and can help drive traffic there), but it can also help you keep tabs on the types of sites linking to you. It is important in maintaining the reputation and focus of your blog - if sites that you deem "inappropriate" are linking to your posts or even perhaps appropriating your content, you should know about it.
Unfortunately, trackbacks - like many other Web 2.0 mechanisms - have become the haven of spammers. Many splogs feed off of the content of other bloggers and their posts. To help manage trackbacks, consider using one of many free websites such as Haloscan.
Backlinks: similar to trackbacks except trackback notifications are generated using an automated program and backlink notification usually comes from search engines such as Google.
While WordPress supports the use of trackbacks, Blogger does not and instead pushes the use of backlinks.
Setting Up Backlinks On Blogger
1. Under Settings, click Comments.
2. Scroll down to the Backinks section. Mark Show and then in the field Backlinks Default for Posts select New Posts Have Backlinks. Click Save Settings.
How Backlinks Are Displayed
Scroll to the end of a post and you will see the backlink under Links To This Post. If there are no backlinks, only the Create A Link prompt will appear allowing a reader to create a link to the post.
Click on the link and the originating post linked to your post will appear.
If you do not want to display a specific backlink, click the trash can icon next to the backlink. The Remove Link To dialog will appear and you can remove the link
Should I Care About Backlinks?
Definitely. First, if a more authoritative blog (one with a large following such as Eastman's Online Genealogy Newsletter) links to one of your posts, it will help channel a large group of viewers to your site. And it improves your blogosphere reputation and "street cred." Second, you should always see who is linking to you and weed out splogs and other nefarious site to which you don't want any connection.
Next: WordPress - How To Effectively Use Trackbacks and Pingbacks
As a reminder, if you have a technical question relating to blogging, feel free to ask by contacting me. If you are wondering about a certain topic chances are your fellow geneabloggers also would like to find out more information.