Arrays are key programming constructs that hold data sets (more than one value). They are an essential part of computer science and data manipulation, and as such are implemented in most major programming languages.
Multi-Dimensional Arrays allow even richer information to be stored than typical or associative arrays.
- PHP: Multidimensional Arrays: http://www.webcheatsheet.com/php/multidimensional_arrays.php
- Using Arrays in PHP: http://www.informit.com/articles/article.aspx?p=31840&seqNum=1