Beginning 10/20/2020, Google Chat will replace Google Hangouts in the Gmail interface. When you open Gmail you will see the Google Chat interface, instead of Google Hangouts (now referred to as "classic Hangouts").

How do I get Google Chat? 

• Explore the new web experience at chat.google.com
• Download the new mobile app for Android or iOS (optionally you can download the latest version of the Gmail mobile app which will have Chat integration built in, similar to the desktop experience)
• Download the new standalone desktop app if you've been using the classic Hangouts Chrome extension or app. You'll be able to access the desktop app from a prompt that will appear inside chat.google.com
• On 10/20/2020, refresh your Gmail inbox to get the new Chat in Gmail experience.

*The classic Hangouts mobile app will no longer function after 10/20/2020 and you will be prompted to install the Chat mobile app, or use the integrated Chat features in the Gmail mobile app.

Where do I find my old chats?

• You will be able to continue recent 1:1 direct messages from classic Hangouts in Google Chat, but group messages from classic Hangouts (including their history) will not be migrated to Google Chat. These group chats will need to be recreated in Google Chat in order to continue the conversation. 
• All previous chat history from classic Hangouts will be accessible in Gmail search.
• The classic Hangouts web interface for chat, hangouts.google.com will remain available during this transition in case you need more time to access and move certain group conversations. Users cannot chat in classic Hangouts by visiting hangouts.google.com in a mobile browser or the Hangouts mobile app. 
• The classic Hangouts bot in Chat will also notify you of missed group messages from classic Hangouts.

*Google will deprecate classic Hangouts entirely by end of year 2020, which means the service will be inaccessible. You will still be able to search for classic Hangouts chats in Gmail.

What are the main features of Chat?

• From Gmail or chat.google.com, you can create a Group Conversation, a Room, or send a direct message.
• Rooms are collaborative spaces where you can invite individuals or entire Google Groups which can contain multiple threads, whereas Group Conversations are strictly a single conversation with a group of individuals. More information on the differences between Rooms and Group Conversations can be found here.
• Chat messages are fully integrated with Gmail across all platforms
• Notification preferences can be set in chat.google.com for all platforms

Where do I go for help?

• Google Workspace Learning Center for an interactive lesson about using the new Chat interface
• Google Support Articles for more detailed information about using Chat
• CIS IT Service Center for more knowledgebase articles or submitting a support ticket