Restricted versus unrestricted picklists
Key Takeaway
A restricted picklist accepts only the values in its value set. An unrestricted picklist blocks new values in the user interface, but the API, automation, and other apps can still save them.
A picklist field gives users a set list of values to choose from. A picklist can be restricted or unrestricted. The difference shows up when data comes in through the API or another app, so it affects how consistent your data stays.
The two parts of a picklist
A picklist has two parts that you manage separately: the field and the value set. The field sets the picklist type and its properties, such as restricted or dependent. The value set holds the choices users see, their order, and the default value.