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.
stem. 1. The main, often long or slender part of a plant that usually grows upward above the ground and supports other parts, such as branches and leaves. Some underground plant structures, such as rhizomes and corms, are stems rather than roots.