What is Facebook Connect used for?
Facebook Connect is a single sign-on application which allows users to interact on other websites through their Facebook account. Launched in December 2008, Facebook Connect works with over 15,000 "partnered" sites to make site access easier for its users.
What is Facebook Connect tracker?
The tracker shows information that Facebook has gathered about your activity off the app in the past 180 days. Facebook learns that information from its advertising partnerships with third-party apps and websites, which voluntarily tell Facebook the identities of people who visit them.