Transitions
A Transition
represents an allowed path between case statuses. An example might be a transition called In Progress which moves a case from the status Open to the status In Progress.
A transition can be possible from multiple statuses but can only move a case to a single status, for example the In Progress transition might take a user from the statuses Open or Submitted to the status In Progress.
You can attach a Form
when you need to capture data on a status change, configure "call to action" buttons and set permissions on who can trigger the transition. Transitions can also be triggered automatically through workflow Rules