The term "n x n" refers to a mathematical expression that represents a square matrix or a grid with equal numbers of rows and columns. In this notation, "n" stands for a variable that can take any positive integer value. For example, a 3 x 3 matrix has three rows and three columns, resulting in a total of nine elements. In various fields, such as computer science and statistics, "n x n" matrices are used to organize data, perform calculations, and solve problems. They are essential in linear algebra, where operations like addition, multiplication, and finding determinants are performed on these matrices, often denoted as matrix or linear algebra.