If you want to bring the entire team’s attention to a post without taking half a second to think about which Team you are actually using, you can use @team instead. @team will resolve to whatever Team into which the message is posted. These shortcuts are only available in Teams channel conversations – typing @team in a private chat won’t do anything.
There’s a shortcut for the current channel too — @channel
The message text is the same using @team and @channel or typing the actual team and channel name.