Luenissla where can I find information about the differences in handling closed tickets or resolved tickets?
That would depend on your designed work flow.
Tickets have two state classifications used by the system currently. they are Open and Closed. Closed tickets (not to be confused with the status of closed) generally means that the ticket is currently done.
Both the default Resolved and Closed ticket statuses that you are asking about are the same programmatically. They do not have to be, and how you train your agents to handle them definitely does not need to be. It's up to you to decide how to use them. They do have one minor configuration difference. Closed tickets re-opened by default become open status. Resolved re-opened status is "system default".
Closed: Allow reopen? yes, re-open status: open
Resolved: Allow reopen? yes, re-open status: system default
You could decide that resolved tickets re-open state is a new status "re-opened", or that once a ticket is "Resolved" it cannot be re-opened. Or you could decide that you do not want to have a resolved status at all.