The digital marketing definition tagging is to add tags, typically visual labels or buttons that appear on interaction, to content. Sometimes called content tags. Tags usually are hyperlinked to a destination URL relating to the content. 

Tagging, in this sense, originated in different forms across various social media and e-commerce platforms. The digital marketing action or tagging process is now commonplace, widely accepted, and available via universal content tagging platforms. Companies like Instagram, Pinterest, and Shopify were early adopters of the product tagging process before becoming a generic process and universally applicable online.