Blackboard Collaborate Ultra is a new version of the old Collaborate. The old version was difficult to access and wasn't always stable, based in part on dependency on the wrong kind of software. The new version is explicitly built for use in web browsers (Note: Google Chrome offers the best experience) and offers easier access and a more stable environment.
Navigating the documentation
Bb has a number of different Collaborate products including both Moodlerooms and the old version. Throughout the tutorials the interface will continually ask you if you're in the right place. You don't want to see content from the original version, you don't need Moodlerooms; We're using Collaborate Ultra and users should avoid guides for SAS, the Original Experience, and Moodlerooms.