What Facebook knows about you
Facebook has been collecting information about you from the moment you created an account. Even though a huge percentage of users don’t like being monitored in a such way, they’re willing to trade-off in order to stay connected to the world’s largest social network.
By visiting the following link, you can see what Facebook thinks it knows about you: https://www.facebook.com/ads/preferences/edit/
Facebook gathers this information for advertising purposes and it is collected in a section called Ad Preferences, which you can find by clicking on the link above. Data is structured in categories with many topics on it.