Only authenticated users can join
What it means to use the "Require authentication to join" feature.
You can choose if you want to use the "Require authentication to join" feature:

"Only UU Zoom Users signed in to Zoom"
If you use the setting "Only UU Zoom Users signed in to Zoom," all participants need to have a Zoom account from Uppsala University and be signed in to that account when joining the meeting. All email addresses within UU ends with ”uu.se;” for example ”@uadm.uu.se,” ”@kemi.uu.se,” ”@student.uu.se.” This will prevent anonymous guests and all Zoom users without a Zoom account from Uppsala University from joining.
"Sign in to Zoom"
If you use the setting "Signed in to Zoom," all users in the world with a Zoom-account and who are signed in can join your meeting. It will keep anonymous guest from joining.
"Swedish University Zoom Users"
If you use the setting "Swedish University Zoom Users," all joining users need to have a Zoom account at a Swedish University or equivalent.
This prevents anonymous guests and Zoom users not affiliated with a Swedish University or equivalent from joining your meeting.
PLEASE NOTE that if you have guest lecturers or other participants who are not from Uppsala University, they cannot join the meeting with this setting.
"Sign in to Zoom"
If you use the setting "Sign in to Zoom," all users in the world with a Zoom-account and who are signed in can join your meeting. It will keep anonymous guest from joining.
"Swedish University Zoom Users"
If you use the setting "Swedish University Zoom Users," all joining users need to have a Zoom account at a Swedish University or equivalent.
This prevents anonymous guests and Zoom users not affiliated with a Swedish University or equivalent from joining your meeting.