Google Chat is a service (app) that allows you to engage in text-based chat.(Google Support Site)
When you receive a message from another user, a notification will appear on the left side of Google Chat. You can start chatting by clicking on the notification.
You can also chat with multiple users by creating a "Space”.
Please note that if the owner (creator) graduates, it will no longer be possible to delete the Space or perform other administrative tasks. Therefore, please be sure to transfer the owner permissions while you are still enrolled.
Google Meet is a service (app) for video conferencing. (Google Support Site)
In the student GWS at Kyoto University, the maximum number of participants per meeting is 100 accounts.
To start or schedule a video meeting, please refer to: "Start or schedule a Google Meet video meeting"(Google Help)
To invite participants to a video meeting, you can either select and add users directly or share the meeting URL with them.