Thrones are the physical "seat of power" of a kingdom.
“The Crystal Throne is the seat of power of the Seanchan Empire, located in the Court of the Nine...Crystal Throne
“The Dragon Throne was the throne used by Rand al'Thor. Rand has the Lion Throne of Andor moved...Dragon Throne
“The Throne of the Clouds is the seat of power in Kandor, located in Chachin's Aesdaishar Palace...Throne of the Clouds