The meeting ID is a 9 or 10-digit number used to identify the BlueJeans or Zoom meeting you want to join. If you received an email invitation to the meeting, you can find the meeting ID in the invitation. Otherwise, the host of the meeting can provide the meeting ID.
Depending on the meeting, you may also need a passcode to join. This is a 4-digit number or a short word or string that proves you're an invited guest. If you received an email invitation to the meeting, you can find the participant passcode in the invitation. (If your invitation from the host doesn't contain a participant passcode, you don't need one—you're all set!)