Google's constellation of online products has long confused me. There is/was Hangouts, Hangouts on Air, Hangouts Chat, Google Chat, Google Workspace, Google Spaces, Google Talk, Google Allo, Google Currents, and probably other products I've forgotten. Now, to make things more confusing, Google is rebranding Duo and Meet, even though it already has a product called Meet.
The Verge says it's less confusing as it seems, but I feel as confused as ever:
If you already have Duo installed, you won't have to do anything. Last month, Google pushed a Duo update that adds the features from Meet, and today, Google's rolling out an update on iOS and Android that will change the Duo logo to the Meet icon. By September, anyone who downloads the Google Meet app will receive the new Meet / Duo combo. Google notes that duo.google.com will redirect to meet.google.com/calling over the next few months.
Now, if you're a Meet user, you don't have to do anything right now if you just want to keep using it as it has always existed without any additional perks from Duo. Google may eventually end support for the original Meet, so just keep that in mind if you wish to continue using the app as-is. Google says it will inform original Meet users when they "should migrate to the new app experience" but doesn't specify when that will happen.