Please be aware that beginning July 19, Zoom will require waiting rooms or passcodes to attend all meetings. According to the company, if your account does not already have either password requirements or a waiting room enabled, Zoom will enable the waiting room for you.
The waiting room feature and passcode feature have a similar purpose, increased security and control for your meetings, but operate in slightly different ways. The waiting room feature gives the host maximum control over exactly who is allowed to enter meeting rooms. Meeting hosts and co-hosts must manually allow every attendee to enter. Passcodes, meanwhile, allow anyone who knows the code to enter. The only people with access to the passcode are attendees, hosts and co-hosts, and anyone the attendees or others send the passcode to.
It’s important to note that meeting hosts will have to check for people in the waiting room and manually allow them to enter. If you choose to add a passcode to meetings that have already been set up, you should resend the meeting invitation to attendants so that they can see the passcode.
You can read more on the FAQ section of their website.