Hangouts Meet finally gains in-call messaging ability in latest update
The former is aimed at enterprise users, while the latter targets consumers. Hangouts Meet is supposed to offer a video calls service, and it's just been upgraded to provide in-chat messaging capabilities.
But that's not all, as Google announced the in-call messaging feature is available cross-platform, which means users can send and receive messages on web and mobile, or just receive them on Chromebox for Meetings.
It's also worth mentioning that anyone using Meet can send and receive messages, even users who are not signed in with Google accounts.
source: Google
Things that are NOT allowed: