If John Bonham opens a ticket they are the From. This does not change unless the ticket is edited.
If an Agent Jones works on it [Agent Jones would appear as the assigned to, if you have claim on response enabled) and ultimately assigns the ticket to Agent Plant.
Assigning it to Agent Plant would become the assigned Agent. Then Agent Plant works on the ticket and assigns it to Agent Page the Supervisor.
Assigning it to Agent Page would make them the assigned Agent. Agent Page reviews the ticket and closes it. Agent Page becomes the Closed By. Closed tickets are not assigned as they are closed.
I imagine that depending on where in the above process you would see two names.
John Bonham and whoever it was currently assigned to.
And ultimately John Bonham and Jimmy Page.
If a ticket is re-opened I believe that it will be automatically assigned to the person who closed it, so it would become assigned to Agent Paige.