What is
Strained yogurt, Greek yogurt, yogurt cheese, labneh, is yogurt which has been strained to remove its whey, resulting in a relatively thick consistency, while preserving yogurt's distinctive, sour taste.
  
Kefir is fermented milk made by using kefir grains containing benefiicial yeast as well as probiotic bacteria found in the yogurt.
  
Origin
Central asian countries like kazakhstan, kyrgyzstan, tajikistan, Middle East
  
North Caucasus regions