The rule 'Github Public Repository Created' is designed to detect the creation of public repositories on GitHub. It triggers when the action 'repo.create' is logged, specifically looking for instances where the repository visibility is set to 'public'. This is significant as public repositories can expose sensitive information if not intended to be shared publicly. Users must verify whether such repositories were intentionally set as public by reviewing the actor responsible for the action and the associated timestamp. The rule incorporates a deduplication period of 60 minutes to minimize repeated alerts concerning the same event.