What is -stan?
1) A suffix in the names of Asian Muslim nations and peoples, including former several Soviet republics and current republics of the Russian Federation: Afghanistan, Pakistan, Turkestan, Tatarstan, Kurdistan. From Persian -stân "place". 2) A superfluous suffix to a place name in general: New Yorkistan, Californistan, Texastan.
Tashkent is the capital of Uzbekistan.