Terma means hidden treasure, and it is a form of retrieving intelligent information from sentient beings, objects and the earth field. In my direct experience, Terma has nothing to do with religion, worshiping idols and it is not exclusive to the practice of Tibetan Buddhism. Padma, has shown images to me that are designed to reflect teachings to generate Gnostic experiences or to relay information during sessions or gridwork, and this recollection of information in the intelligent field is called Terma. The language we share is of the Diamond Heart path, which transcends all culture, language or teachings. Padma is connected to the Aurora Guardians.
Terma from Wiki
Terma (Tibetan: གཏེར་མ་, Wylie: gter ma; "hidden treasure") are various forms of hidden teachings that are key to Vajrayana or Tibetan Buddhist and Bon religious traditions. The belief is that these teachings were originally esoterically hidden by various adepts such as Padmasambhava and dakini such as Yeshe Tsogyal (consorts) during the 8th century, for future discovery at auspicious times by other adepts, who are known as tertöns. As such, terma represent a tradition of continuous revelation in Vajrayana or Tibetan Buddhism. Termas are a part of tantric literature.