Vajji was a mahajanapada towards the north of Ganga in the division of Tirhut. It was a confederacy of eight or nine clans. The capital of Vajji mahajanapada was situated at Vaishali.
Viharas were for the purpose of living, Chaityas were assemblies for the purpose of discussions. Further, Chaityas were with Stupas, Viharas did not have stupas.