**Matrix Definition:**

A **matrix** is a ordered rectangular array of numbers arranged in rows and columns. The array of numbers below is an example of a matrix.

The numbers of rows and columns that a matrix has are knows as dimensions or order of a matrix. By convention while expressing order of a matrix, rows are listed first and columns are listed second. Thus we can say order of the above matrix are 4*3 i.e. matrix has 4 rows and 3 columns.

Numbers appearing in a matrix are known as “Element” of a matrix. In the above matrix the element in second row and second column is 95.

**Matrix Notations**: While working on matrix, we commonly use certain symbols to identify an element of a matrix.

**Matrix Element**: In the below given matrix elements are represented symbolically.

By convention, first subscript refers to the row number; and the second subscript, to the column number. Thus, the first element in the first row is represented by A11. The second element in the first row is represented by A12. And so on, until we reach the fourth element in the second row, which is represented byA24.

**Types of a Matrix**:

There are several types of matrix but below is the list of most commonly used matrix:

- Rows Matrix
- Columns Matrix
- Rectangular Matrix
- Square Matrix
- Diagonal Matrix
- Scalar Matrix
- Identity Matrix
- Triangular Matrix
- Null or Zero Matrix
- Transpose of a Matrix

We will cover introduction of each of the above given in the following chapters