Pixel is a snippet of code that is located on the affiliate link or on the pages where sales or transactions are generated. When a user clicks somewhere around the pixel, it is fired, meaning the click ID, sale, or transaction is generated. Consequently, marketers can track or receive notifications when the affiliate link was followed or a sale/transaction happened.
Ad Exchange
An ad exchange is a marketplace where publishers sell advertising space to advertisers. It works as a real-time auction: publishers provide information about advertising space: