Inviting participants with public link generates a link that can be shared with others to invite more people. These links can be used by multiple people, multiple times while the meeting room is active.
Inviting participants with a private link generates a link that can only be used once. Participants will not be able to forward the link to other people, so the meeting will stay private and secure.
Inviting participants via email sends an invitation link directly to participants. After entering their email addresses, they will receive the link in their inbox, so there is no need to copy and paste anything.