An array is a data structure that stores one or more similar type of values in a single variable.
There are three different kind of arrays and each array value is accessed using an ID c which is called array index.
Indexed arrays : An array with a numeric index. Values are stored and accessed in linear fashion.
Associative array : An array with strings as index. This stores element values in association with key values rather than in a strict linear index order.
Multidimensional array : An array containing one or more arrays and values are accessed using multiple indices.