Business processes and record types
Key Takeaway
You can't customize a lifecycle picklist, such as Stage or Status, directly on a record type. To give two record types different values, assign a different business process to each one.
Record types let different groups of users work with the same object in different ways. A business process is a set of values for an object's lifecycle picklist, so different teams can track their own sales, support, or lead lifecycles.
What record types let you offer
Record types let you offer different business processes, picklist values, and page layouts to different users of the same object.
For example, regular sales deals and professional services engagements can get different picklist values. Customer support cases and billing cases can show different page layouts.