Applies to: Microsoft Teams.
Desktop
You begin one-on-one and group chats the same way: by pressing New chat at the top of your chat list.

Start a one-on-one chat
After you’ve chosen New chat and typed the person’s name, create your message in the box at the bottom of the chat. To open your formatting options, click Format
underneath the box where you input your message.

Once you’re finished, press Send . This commences the chat.
You can even begin a one-on-one chat from someone’s profile card. Access it by selecting their picture in a channel or from a search.
Start and name a group chat
Launch one the same way you begin a one-on-one chat: click New chat at the top of your chat list. Press the down arrow to the far right of the To field and write a name for the chat in the Group name field. Then, state the sought names of the people you want to add in the To field.

This begins a new conversation. Everyone who has access to the group chat can send messages.
You can add up to 100 people in a group chat.
Add people to the conversation
To loop more people into the conversation, simply press Add people (or View and add participants in group chat) in the top right corner of Teams. Then, enter your desired individuals’ names you want to chat with, choose how much of the chat history to contain, and select Add.
Note: When adding someone to a group chat (not a one-on-one), you can include the chat history.

Teams will retain the entire chat history, right back to the original message. And if anyone leaves the group, their chat responses are intact in your chat history.
See who’s in a group chat
To view who’s in a group chat, hover over the amount of participants in the chat header to display a list of everyone’s names.
