Google Meet Help Centre
Video calls on Google Meet can be useful for holding online meetings when in-person meetings aren’t possible. In Google Meet, you can also dial in or dial out using a phone to join meetings (you will only have voice capabilities in the dial in/out option). Video calls are similar to other tools available at TMU such as Adobe Connect, but with fewer features. If you have a camera and microphone for your computer or device, you can start a video call with up to 250 participants and share your screen.
Hangouts still exists but will strictly be used for text based chat and phone calls. Google Meet will be a dedicated video conferencing app instead of being part of classic Hangouts. After August 13, 2018 Calendar events will include options to create Meet meetings and all classic Hangouts links will become inactive.