Workgroups are collections of projects/gigs/chats which needs to be accesses by a different team of users (like a another branch, department or company). The good news is that if you select the "All worgroups" options it shows all the gigs from all the workgroups and even your own private projects all in one location.
The main difference in a workgroups is that you can register your team, staff, or group of people that will work in that workgroup. All team members of a workgroup can see all the public projects and tasks of all the other team member on the same workgroup. However if projects/gigs are set to be private then only the invited participants on the workgroup will be able to see that project or gig. Soon you will be able to assign specific tasks and workflow sets to workgroups.
Note: you have to select a workgroup to change settings in that workgroup. If you select i.e "ALL Workgroups" the group settings will not be visible.