Explanation
A support process is a feature that allows administrators to define and enforce the stages that a case or work order must go through based on its record type. A support process determines which values are available for the status field for each record type. If a support process omits a certain value for the status field, such as Closed, then users will not be able to see or select that value when working with cases or work orders of that record type. References: https://help.salesforce.com/s/articleView?id=sf.customize_supporthome.htm&type=5