The Facebook pixel is an analytics tool that allows you to measure the effectiveness of your advertising by understanding the actions that people take on your website.

You can use the pixel to:

Make sure that your ads are shown to the right people. Find new customers, or people who have visited a specific page or taken a desired action on your website.
Drive more sales. Set up automatic bidding to reach people who are more likely to take an action that you care about, such as making a purchase.
Measure the results of your ads. Better understand the impact of your ads by measuring what happened as a direct result.