Online Interview - International Student

Hi!

I'm a student from a middle eastern country with no interviewers available. I was contacted by an admissions officer and was offered an interview over video chat. I've never had the experience and don't know how to get ready.

Does anyone here have the experience?
Do admissions officers mostly ask about myself and why I applied to Harvard or they might ask other types of questions as well?

I'd be really grateful if you guys could help me!