Facebook pixel is a cookie served through Javascript protocol served from your website to track users and retarget them on Facebook and Facebooks Audience Network.  A Facebook pixel is a 1×1 image that is served to the browser that establishes a connection with your server.  Facebook pixels are far more powerful than other advertising platforms as Facebook can track the user across many devices.  

Facebook will know if you are accessing Facebook.com through mobile or through a desktop computer and that is technically speaking makes Facebook so powerful!  When the same user takes an action on your ads (i.e., clicks or comments on your Facebook Ad), on both of the channels, Facebook will not count that as two users.  Facebook changed its pixel architecture a few years ago and now it has a one-pixel base code.  The new Facebook pixel now loads 3x faster than the previous Facebook pixel.  

An event is any action on your website that can be tracked as when someone comments or clicks a button.  There are 9 events that can be used for tracking purposes, as noted below…

1. Page Views

2. Leads

3. Search

4. Purchase

5. Checkout Initiate

6. Add to Cart

7. Add to Wishlist

8. Complete Registration

9. Add Payment Information