The words retargeting and remarketing are interchangeable. Most people know about retargeting through the Facebook pixel, which is a tiny code snippet you add to your website. When someone lands on a page with this code, the Facebook pixel sends a message back to Facebook, saying something important is happening.
Facebook has opened up new ways to retarget people (or show them content or ads based on prior actions), including video retargeting.
Because Facebook has been emphasizing live video and video in the news feed, Amanda is especially excited about these video retargeting features. Anytime somebody sees at least three seconds of a video (recorded or live), Facebook takes note of who they are and puts them into a retargeting custom audience that you can use to retarget them again and again.