What is that and how do i install it?
You can go through Tools>>Add Ons or just do a web search for Ghostery. That will take you to a page where you can get it installed in Firefox. Restart your browser and then when you visit a site, you'll see a small dark popup box in the upper right with names of trackers, etc. in white.
Right click on the little Ghostery icon in the status bar at the bottom of Firefox and then select to block whatever you like. Me? I block 'em all. When it shows up in white in the popup, I block it. I don't care what it is. Though in the Ghostery settings you can get info on what each of them is.