An Apsaras is a nymph (devastrī). These apsarā women were born at the churning of the ocean of Milk. [Vālmīki Rāmāyaṇa, Bālakāṇḍa, Chapter 45, Verse 32] ;[Viṣṇu Purāṇa, Part I, Chapter 9] ;[Agni Purāṇa, Chapter 3] . There are thousands of Apsaras. (Details given against the names of Apsaras).
Note: *) Ariṣṭhā, a wife of Kaśyapa, delivered thirteen Apsaras. They were: Alambuṣā, Miśrakeśī, Vidyutparṇā, Tilottamā, Rakṣitā, Rambhā, Manoramā, Keśinī, Subāhu, Surajā, Suratā and Supriyā. Ariṣṭhā gave birth also to four Gandharvas, Hāhā, Hūhū, Atibāhu and Tumburu as mentioned in the following verse. Ariṣṭāsūta Subhagādevī devarṣitaḥ purā Alambuṣā miśrakeśī Vidyutparṇā Tilottamā Aruṇā rakṣitā caiva rambhā tadvat manoramā Keśinī ca subāhuśca vikhyatau ca hahāhuhū Tumburuśceti catvāraḥ smṛtāḥ gandharvasattamāḥ.]