An ordered arrangement of data items. A vector is a one dimensional array; a matrix is a two-dimensional array. Arrays are used in myriad applications from basic database processing to scientific simulation. Most programming languages support arrays by providing indexes into the data. For example, with indexes starting at zero, the hypothetical programming statement Employee
points to the fifth record (row) and tenth data item (column) of an employee array. See subscript
and data item
With array indexes starting at 0, in the top array, City would be programmatically identified as Customer (fourth data item). Sales would refer to the March figures for Widgets in the bottom array.