What do the different roles (like host, co-host, participant) in Zoom mean?
Host: The user that scheduled the meeting. They have full permissions to manage the meeting. There can only be one host of a meeting. The host can do pretty much anything in the course.
Co-hosts: Shares most of the controls that hosts have, allowing the co-host to manage the administrative side of the meeting, such as managing attendees and breakout rooms, as long as you have version 5.4.6 of Zoom or higher.. If a host needs someone else to start the meeting, they can assign an alternative host in settings for the meeting in the portal / website.
Alternative hosts: Shares the same controls as co-hosts, and can also start the meeting. Hosts can assign alternative hosts when they schedule a meeting.
Check out this support page for more information about roles: https://support.zoom.us/hc/en-us/articles/360040324512-Roles-in-a-meeting.