A workgroup is a position your organization can be reached at, and the unit that hands out access. It can be a desk — "AOG Desk", "CGN MCC", "Line Maintenance" — or a team. Either way it outlives whoever is filling it, which is the whole reason it exists as a thing separate from the people in it.
It does two jobs at once
It is a routing target. A contact can point at a workgroup rather than at a named person, so when the night shift changes, nothing about your published contact details has to change with it. A requestor reaching your AOG desk reaches the workgroup, and the workgroup reaches whoever is in it today.
It is the unit of authorization. The workgroup carries one access profile, and everyone in it inherits what that grants. Permissions never sit on a person.
A workgroup is whatever your organization actually routes work to. It might be a desk somebody staffs — "AOG Desk", "MCC". It might be an operational team — "Line Maintenance", "Hangar 2 Base Maintenance", "Technical Records". It might be a shift or a crew — "Night Shift", "Flight Crew". A workgroup with one person in it is normal, and so is one with thirty.
Those two jobs are why a workgroup is worth naming after the position and not the people. "CGN MCC" keeps working; "Mehmet's desk" does not.
Giving it an access profile — or not
Every workgroup carries at most one access profile. Leaving it empty is a real and common choice: a workgroup with no access profile still exists, can still be messaged, still be routed to, and still appear in the provider directory. It simply grants no portal access. Most contact desks want exactly that.
The picker shows "Grants nothing" for this, and it means what it says rather than warning you about something.
Scope: the whole organization, or one station
A workgroup is organization-wide by default. Give it a station and it narrows to that station — useful for "IST AOG Desk" as distinct from a central one. Leave it organization-wide for anything that answers for the company as a whole.
Being found
A workgroup can be listed in the provider directory. Two things have to agree for that to happen: the workgroup's own discoverable setting, and your organization's directory setting above it. A workgroup with nobody in it is never listed, whatever those say — there would be nobody to answer.
Leads
A lead is who gets chased when the workgroup needs an answer. It grants nothing extra. Removing somebody as lead only takes them off that duty; it does not take them out of the workgroup.
Archive, never delete
You archive a workgroup to retire it. There is no delete, and that is deliberate: message history names the workgroup a message was sent as, and deleting one would leave conversations attributed to nothing.
Archiving takes effect immediately for access — an archived workgroup grants nothing to anybody, so check who is in it before you archive one. Archiving can never lock the organization out: its owners are its administrators by being owners, and owners are not in any workgroup.