In what way do view-through conversions get counted?

They get counted as conversions that are recorded when users view and interact with an ad, then never convert.
They get counted as conversions that are recorded when new users view and interact with an ad, then later convert.
They get counted as conversions that are recorded when repeat users view but don’t interact with an ad, then later convert.
They get counted as conversions that are recorded when users view but don’t interact with an ad, then later convert.