Vaadi And Samvaadi

Other than Sa and Pa the swaras that give the foundation and a chaya (uniqueness) to the raag is what is Vaadi and Samvaadi

Usually 3 to 4 swaras apart
Vaadi and Samvaad - unless there's Samvaad (dialogue) it doesn't become samvaadi swar.

Wadi swara and samwadi - king and prime minister of the court.