To place a call on hold, click More actions in your call window and select Hold. Everyone in the call will be notified that they've been put on hold, and you can continue your call by clicking Resume.
People on hold can't see or hear anyone else in the call, including you. Screen sharing is temporarily suspended, too. Everything will return to normal once you resume your call.
To place a call or meeting on hold, tap More options in your call window and select the hold option. To continue the call, tap Resume.