Two-dimensional arrays are used whenever the model data is best represented with rows and columns, or has two varying aspects (eg, gender and age, weight and height, ...).
Each cell of the array is a variable that can hold a value and works like any variable. As with one dimensional arrays, every cell in a 2D array is of the same type.
Important: Each cell of the array is specified with a row and column number, in that order.
2-dimensional arrays are usually represented with a row-column "spreadsheet" style.
