https://www.facebook.com/business/learn/facebook-ads-pixel

Ever wondered how Amazon or other websites follow you back to Facebook with the latest items you just looked at? Amazon and similar companies use Facebook Pixels.

What is Facebook Pixel? The Facebook pixel is a piece of code that you place on your website. It collects data that helps you track conversions from Facebook ads, optimize ads, build targeted audiences for future ads and remarket to people who have already taken some kind of action on your website.

For example, when customers visit your website, the Pixel records that visit. Then when customers go to their Facebook page, your website and products may show up on their activity feed or the Facebook sidebar.

For instructions on How to Set Up and Install a Meta Pixel, go to: https://www.facebook.com/business/help/952192354843755