Trackbacks option in blogs

I am only over a month old in blogging and I have a question about trackbacks as this is a grey area for me. I see that some blogs do have this feature, some don't. Is there a rule about this OR it is just to the discretion of the blogger (configurable?), OR I just don't see the trackback options on some food blogs (I might not be looking in the right place?)

Thanks a lot

Bea at La Tartine Gourmande
www.beaskitchen.com/blog