What do Record Types do in Salesforce?
Record Types allow administrators to configure different page layouts, business processes, and picklist values based on a User’s profile.
Does Record Type have an impact on record security?
No, not on it’s own.
When is using a Record Type appropriate in Salesforce?
Different values based on another field where Dependent/Controlling fields are not applicable (i.e. Standard fields).
Different values based on Profile/Process