What does "digital footprint" mean?

A digital footprint is trail a user leaves every time he surfs the Internet or uses a website. When users engage in such activities as sending emails, uploading or downloading videos and pictures, or filling out registration forms online, bits of personal information are left behind for others to track.

Leaving behind personal information can make a person a target for hackers, cyber thieves and anyone who might aim to use another person's information for personal or economic gain. It can also leave a person open for breeches of personal safety if a home address or phone number can be found.