Interrogatives are sometimes called question words. They introduce both direct and indirect questions. When introducing indirect questions, they function somewhat like relative pronouns/adverbs.
Interrogates are also sometimes called W-words, since they almost all start with W: who, whom, whose, which, what, where, why, when, how.
Whose laptop is this?
What’s for dinner?
How do I work this scanner?
Elvis knew whose laptop it was.
I wondered what was for dinner.
I had no idea how to work the scanner.