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.
What is a Valve Stem? The valve stem is a small, tube that protrudes from the tir eand is most often made of metal and rubber. The most common type of valve stem used in passenger vehicles is the Schrader valve. These are rubber valve stems with a metal tip that is threaded like a crew for the valve cap. These valve stems are also used on bicycles and motorcycles, though the construction materials may differ.