Zoom has two principle types of security (to make sure authorized persons enter the Zoom session.)  One type of security is the use of a passcode.  To enter the Zoom session, the user must enter a passcode assigned by the organizer.  The other is a waiting room.  When a user logs onto the Zoom session, he/she is put into a waiting room.  The host of the session receives a message that there is someone waiting.  The host then enables the use to enter the session after he/she is validated by name or other means.  Open Zoom sessions (like a Bible class)  use the waiting room while Memorial Service uses a passcode.