Your digital footprint is basically the trail of breadcrumbs you leave behind...

https://www.morning-times.com/article_d7d0946a-6b1c-4ec9-8dd2-46f5ecbcd932.html

Your digital footprint is basically the trail of breadcrumbs you leave behind whenever you browse, shop, or use apps. Advertisers use these pieces of your history to build a profile and target you across the web