When using Microsoft Teams, one of the first features that users gravitate to is Chat. Chat is at the center of whatever you do in Teams. From individual chats with just one other person to group chats and conversations in channels—chat has you covered.
Chats can be one-on-one or in a group.
Sometimes you’ll want to talk one-on-one with someone. Other times, you’ll want to have a small group chat. In Chat, you can do either.
You start one-on-one and group chats the same way: by selecting New chat 
at the top of your chat list. Once in a chat, you’ll be able to send messages that include files, links, emojis, stickers, and GIFs—whatever you need to get your point across!
Here are some more details about each kind of chat.
One-on-one chat
Once you’ve selected New chat 
and entered the person’s name, compose your message in the box and select Send 
. This starts the chat.
Group chat
Use a group chat when you need to talk to a small group of people. Start one the same way you start a one-on-one chat: select New chat 
at the top of your chat list. Select the down arrow to the far right of the To field and type a name for the chat in the Group name field. Next, type the names of the people you’d like to add in the To field.
Once the chat has begun (whether group or one-on-one), just click it in the chat list to dip back into it and send more messages.
Chat happens in channels, too.
When you go to any channel in Teams the very first tab is Posts. Think of this as one big group chat. Everyone who has access to the channel can see the messages on the Posts tab.
You’ll have to judge based on your organization and culture what messages are suitable for the Posts tab in a particular channel.
The other important thing to know about messages in a channel is that replies to a channel message stay attached to the original message. This way, the whole thread of the conversation can be easily followed by anyone reading it. This is the beauty of threaded conversations!
To reply to a channel message, be sure to use the little Reply link underneath the message.
