Algebra is an important branch of mathematics. Matrix theory is a very useful topic that comes under linear algebra. Matrix theory is all about the study of matrix (plural – matrices) Matrix is an arrangement of elements, especially numbers, in a particular way. It’s a rectangular array that contains numbers, trigonometric expressions, symbols etc, each of which is known as an element of matrix. A matrix does have rows and columns. Rows are represented horizontally, while columns are shown vertically.