Displaced Person

Persons or groups of persons who have been forced to leave their homes due to violence, violations of human rights, armed conflict or natural or human-made disasters,

Internally Displaced Person (IDP)

Same definition as above but has not crossed a national border.  Many of the world’s refugees are IDPs within their own countries of origin.

Pop Quiz

Is a refugee also a displaced person?

Answer

Yes, but the burden of proof lies on them to show they are not only displaced but cannot return to their country due to a reasonable fear (see Refugee).

https://www.iom.int/key-migration-terms