Tracker based campaigns are those types of AR campaigns that require a tracking image to be uploaded and used as a reference on which the digital content will be displayed.
In a tracker based campaign, you can upload a tracking image and design a personalized AR experience over and around the tracker. Place assets and set interactions to boost user interactivity with your experience. Once published, scan the tracker image and view your AR campaign.
Follow the link to read more about tracker image quality requirements and recommendations