The four foundational texts of Vedic Sanskrit literature (the Rigveda, Samaveda, Yajurveda, and Atharvaveda), composed during the Vedic Age (roughly 1500 to 600 BCE) and central to early Indian religion and society.
Veda-to-content matching (hymns, music, rituals, charms), the location of the Gayatri Mantra and Purushasukta in the Rigveda, and the Shruti versus Smriti distinction are standard Vedic-age facts.
Shruti (the Vedas, revealed) versus Smriti (remembered texts like the epics, Puranas, and Dharmashastras); the Upanishads are the concluding philosophical part of the Vedas (hence Vedanta), not a separate fifth Veda.
Rigveda (hymns), Samaveda (melody), Yajurveda (rituals), Atharvaveda (charms); each with Samhita, Brahmana, Aranyaka, and Upanishad.