I have participated in multiple types.

1:1 code review in person, sort of like pairing at that point. 1:1 remote via PR, 1:N in person in front of a screen or projector, 1:N remote where you need multiple approvals and different sections may interest different people, and N:M where a small team worked on a feature and request another teams review.

I think of review broadly as the remote/pr kind. But all of these are valuable in different situations.