To place a call on hold, select Hold at the top of your call window. You won't see this option if you're in a scheduled Teams meeting.
Everyone on the call will be notified that they've been put on hold, and you can continue your call by selecting Resume.
People on hold (including you) won't be able to see or hear anyone else on the call. Screen sharing is temporarily suspended, too. Everything will return to normal once you resume your call.
The maximum number of calls you are able to put on hold is limited to five at a time, with one active.
Calls on hold can't be transferred to group calls. Take the call off hold to transfer it to a group call or to add someone else to the call.