What is Google Hangouts used for?

Google Hangouts is part of Google’s G Suite, enabling both one-on-one chats and group chats with up to 25 people at a time

You can use Hangouts to start a chat conversation, video call, or phone call using Wi-Fi. Hangouts sync automatically across devices. If you start a Hangout on your computer, you can continue your chat on another device, such as your phone, for example. Hangouts enables students, faculty, and staff to collaborate anytime, anywhere.