A 2x2 matrix is a rectangular array of numbers arranged in two rows and two columns. It is commonly used in mathematics and statistics to represent data or perform calculations. Each element in the matrix can be identified by its position, with the first index indicating the row and the second index indicating the column. In various fields, such as economics and computer science, 2x2 matrices can help visualize relationships between two variables. They are also used in linear algebra for solving systems of equations and in game theory to analyze strategic interactions between players.