Sart is a name for the settled inhabitants of Central Asia and South Asia, which has had shifting meanings over the centuries. Sarts, known sometimes as Ak-Sart ("White Sart") in ancient times, did not have any particular ethnic identification, and were usually (though not always) town-dwellers. Since the 16th century and onward Mughal historians referred to the Tajiks of the Kabulistan (now Afghanistan) and surrounding regions as Sarts.
Read more about Sart: Origin, Alternative Meanings, Development of Ethnic Identity in Central Asia, Modern Meanings, Use By The Dongxiang, Use in Siberia