Matrix can have only two dimensions, whereas an array can have as many dimensions as you want. Matrix is defined with the help of data, number of rows, number of columns, and whether the elements are to be put in row-wise or column-wise.
In array, you need to give the dimension of the array. An array can be of any number of dimensions, and each dimension is a matrix. For example, a 3x3x2 array represents two matrices, each of dimension 3x3.