Public revelation refers to the deposit of faith that God entrusted to the Apostles. Therefore, public revelation ended with the death of the last Apostle (John), since there were no longer any apostolic eyewitnesses to Jesus’ teaching and ministry. So examples would be the miracles He performed, the divine presence in the Eucharist, etc.
Private revelation is any apparition or message that has been given since then. Though the church may deem some private revelations acceptable and worthy of belief (or not), no one is bound to believe any private revelation. Examples of approved private revelations would be the appearance of Mary at Lourdes, or Fatima. Both of which are easily searchable.
Hope that helps.
