Cases have four default statuses, but you can add as many as you need to track your case's progress.
Default Statuses
Every case transitions through "New", "Open" and "Closed" statuses and may become "Escalated".
A case is "New" from the time it is raised until it is assigned to a user group, at which point it is "Open". As cases are assigned as soon as they are raised, this "new" state will show up in case history records, but in practice, isn't used.
A case will have the "Escalated" status either when it passes it's SLA, or is manually escalated by the case manager. See SLAs and Escalations for more information.
The "Closed" status is how all cases of a certain type will appear once closed. You can only have one closed status, but a case manager can provide a close reason and additional notes at the time they close the case.
Additional Statuses
You can create additional "open" statuses in the Status section of the case configuration. These are often used to represent various "in progress" stages, and can be set and picked by a case manager during the case lifecycle.
Routines
Changing the status of a case can also act as a trigger point for Case Routines. Routine actions can also set the status of a case.