A tuple is a fixed fixed-length list containing elements that need not have the same type. It can be, and often is, used as a key-value pair. A row (sometimes called a record) is the set of fields within a table that are relevant to a specific entity.
The stem wall on a concrete foundation is essentially the supporting wall that joins the foundation of a building to the vertical walls of the structure that is constructed atop the foundation.
The Great Wall of China, in Shanhaiguan. The Great Wall of China is an ancient wall in China. The wall is made of cement, rocks, bricks, and powdered dirt. It was built to protect the north of the empire of China from enemy attacks. It is the longest structure humans have ever built.