Facebook retargeting is a form of online advertising that allows businesses to show ads to users who have previously visited their website or engaged with their business on Facebook. The ads are shown to users as they browse other websites or use Facebook, and they are designed to remind users of the business and encourage them to return to the website or make a purchase. Facebook retargeting is based on the use of cookies, which are small pieces of data that are stored on users’ devices when they visit a website. These cookies allow businesses to track users’ online activities and show them targeted ads based on their interests and behaviors. Retargeting can be an effective way for businesses to nurture leads and drive sales.