What Is the Facebook Pixel?
The Facebook pixel is a piece of code you place on the backend of your website to track visitors to your site. The pixel allows you to run highly targeted campaigns, so it's important to install it before running Facebook ads.
Each ad account gets one default pixel to use. The code is made up of two main parts: the pixel base code and event code. The pixel base code tracks all of the traffic to your site. Event codes are additional pieces of code you can add under the default pixel code to specific pages of your website that allow you to track certain actions on those pages.
A Facebook pixel is code that you place on your website. It helps you track conversions from Facebook ads, optimize ads based on collected data, build targeted audiences for future ads, and remarket to qualified leads—people who have already taken some kind of action on your website