What is a kolba in the book A Thousand Splendid Suns?

In the book "A Thousand Splendid Suns" by Khaled Hosseini, a kolba is a small, traditional Afghan mud hut that serves as a shelter for individuals or families. It is typically located in rural areas and is made of mud bricks and thatched roofs. Kolbas are often simple structures with minimal amenities, reflecting the harsh living conditions faced by many Afghan people.