In the Participants section, beside every participant, there is a hand button. A participant can use this button to raise/lower their hand in a meeting, or a moderator can use it to lower participants’ hands. This is traditionally used when someone is giving a lecture and all participants are muted. When a participant “raises their hand”, the lecturer (a moderator) knows to unmute him/her and see what he/she has to say. The moderator can then lower the participant’s hand. This is demonstrated in the image below, where John is the moderator who is giving a lecture, and so his participant (Jane) is muted. Jane raises her hand by clicking the hand button and her hand turns green. John can see this, and when he is ready, he will unmute Jane so she can speak.
There is also a global “Lower All” button located in the title bar at the top of the meeting dashboard. This can be used by the moderator to lower all raised hands in one click.