A digital footprint, sometimes called a digital dossier, is the body of data that exists as a result of actions and communications online that can in some way be traced back to an individual.
Digital footprints are sometimes broken down into active and passive data traces. Active data traces are the ones that the user leaves intentionally. Facebook, Twitter and blog posts, social network connections, image and video uploads, email, phone calls and chats are among the ways people create active digital footprints.
Passive data traces connected to an individual are left by others or gathered through activities that the user does without purposefully putting out data. Website visits and actions, searches and online purchases are among the activities that add passive data traces to a digital footprint.
A digital footprint is relatively permanent and once the data is public -- or even semi-public, as may be the case with Facebook posts -- the owner has little control over how it will be used by others. For that reason, a major focus of digital footprint management (DFM) is caution about online activities to control the data that can be gathered in the first place.
See a video following a single individual's digital footprint: