Record types for layouts and picklists
Key Takeaway
Record types let one object offer different picklist values, page layouts, and business processes to different users. They are not a visibility control.
A record type sets up an object differently for different users. For example, you can separate regular sales deals from professional services engagements with different picklist values for each, or show support cases and billing cases with different page layouts. You give users access to record types through profiles and permission sets, and you map page layouts to each profile and record type pair.
What record types do and don't do
For example, imagine that only your Consulting division gets leads through seminars. A Consulting record type can show the Seminar lead source, while a Hardware record type hides it.
Assigning a record type only lets a user use it when they create or edit a record. Users can still view and edit records whose record type isn't enabled for their profile.