The simplest type of data structure is a linear array. Also known as a one-dimensional array. An array holds several values of the same type (Integer, Floats, String, etc.). Accessing elements within the array is very fast. An array is normally of fixed size. After the size of the array is defined at the start, it may not be possible to increase the size of the array without creating a new larger array and copying all values into the new array. In computer science, an array data structure or simply an array is a data structure consisting of a collection of "elements" (values or variables), each identified by at least one "array index" or "key". An array is stored so that the position of each element can be computed from its index tuple by a mathematical formula.