Sabha, Samiti, and Vidatha were the main tribal assemblies. Parishad became more prominent in later periods (though sometimes mentioned, it wasn't a primary popular assembly like the others in early times).

Initially, in the Early Vedic period, the Varna system was flexible and based on occupation. It became hereditary and rigid (based on birth) in the Later Vedic period.

Painted Grey Ware (PGW) is the distinctive pottery style associated with the iron-using culture of the Later Vedic period in the Gangetic divide.

Varuna was the ethical god who maintained 'Rita', the cosmic and moral order of the universe.

The word for daughter, 'Duhitr' (source of the word daughter), literally meant 'one who milks the cow', reflecting the pastoral nature of society.

Gargi Vachaknavi was a philosopher mentioned in the Brihadaranyaka Upanishad, which belongs to the Later Vedic period. She famously debated Yajnavalkya.

The Ashvamedha (Horse Sacrifice) was a grand ritual performed by powerful kings to demonstrate their sovereignty and imperial authority over the lands traversed by the sacrificial horse.

In the Rigveda, 'Ayas' likely referred to copper or bronze. Iron is specifically referred to as 'Shyama Ayas' or 'Krishna Ayas' in later texts.

Sage Vishvamitra is credited with composing the Gayatri Mantra, found in the third Mandala of the Rigveda.

Vitasta is the Rigvedic name for the river Jhelum.