The Steiner system is a mathematical concept used in combinatorial design, specifically in the area of block designs. It involves a set of points and a collection of subsets, called blocks, that satisfy certain conditions. The most common type is the Steiner Triple System, where each block contains exactly three points, and every pair of points appears in exactly one block. These systems are named after the mathematician Jakob Steiner, who contributed to their development in the 19th century. Steiner systems have applications in various fields, including statistics, computer science, and design theory, where they help in organizing data and optimizing arrangements.