As we have previously stated, the basic data element in the MATLAB system is the array. A scalar is represented as a array—that is, an array with one row and one column. Vectors are one-dimensional arrays. An array is called a column vector, where m is the number of rows in the single-column array. A array is called a row vector, where n is the number of columns in the single-row array. Array elements may be numbers, characters, strings, other arrays, or structures. Recall that the elements in an array must be uniform. A special type of array, called a cell array, allows nonuniform elements. MATLAB supports multidimensional arrays. A matrix is a special case of an array. A matrix is a rectangular array containing elements of any specified algebraic system, usually real or complex numbers. The English mathematician Arthur Cayley first introduced the concept of a matrix in the mid-19th century. Matrices are employed to help solve systems of linear equations and to perform linear transformations. This chapter describes several applications of matrix algebra to scientific and engineering problems. MATLAB arrays are, by default, self-dimensioning. That is, if we initialize an array with a set of values, MATLAB automatically allocates the correct amount of space for the array. If you append an element to an array, MATLAB automatically resizes the array to handle the new element. This is different from many programming languages, where memory allocation and array sizing takes a considerable amount of programming effort.