There are number of functions that enable a host/moderator to manage the flow and interaction-level of meeting participants.
The moderator has the power to mute others, disable their video, or even remove them from the chat room.
Furthermore, in the text-chat section, there is a tab for polls to be created.
The host has also the ability to set a password for more security of undesired participants - as well as a lobby, where people have to enter a username first.
Here are some more articles to get you started with Jitsi: