Question

why is the early Vedic period referred to as the rig Vedic period​

Answer 1

The hymns of rigveda might've been created long ago but all the 10 mandals were “compiled” during 1500 BCE just like a book of old short stories is published several years later. Since the Rigveda is considered the oldest of all the vedas, the Early vedic period i,e. 1800–1500 BCE is also called the Rigvedic period.