A digital footprint refers to the trail of data one leaves behind while using the internet, which includes online activities, interactions, and data-sharing practices. It is categorized into two types: active and passive footprints. Active footprints are created when users intentionally share information, such as through social media posts, while passive footprints are generated without direct interaction, like tracking cookies. Understanding one's digital footprint is important as it can impact privacy and how individuals are perceived online. Managing it effectively can help protect personal information and enhance online reputation.