In this video I quickly go over the history behind Defender EASM, and how to get started with it.

As Microsoft defines it:
"An external attack surface is the entire area of an organization or system that is susceptible to an attack from an external source. An organization's attack surface is made up of all the points of access that an unauthorized person could use to enter their system. The larger your attack surface is, the harder it's to protect."
https://learn.microsoft.com/enus/azu...