What does it mean by Limited Data usage?

What does it mean by Limited Data usage?

Snap is committed to providing privacy-centric solutions that align with rapid industry and regulatory changes. To provide businesses with more control over how their data is used by our systems and better support their internal compliance requirements, they offer a Limited Data Use parameter. Currently, Limited Data Use can be used to identify when a conversion event is tied to a user who has opted out of tracking under Apple’s ATT policy.