in php it's quite simple to understand:
an array is a "chain" of variables of variables of the same name, distinguished only by its index, e.g.:
$variable = "ooo";
$myarray = array("1", "2", "zuzuzu", $variable);
thus:
$myarray[2] contains "zuzuzu".
$myarray[3] contains "ooo".
now, instead of storing variables in an array, try storing arrays in an array:
$anarray = array(1, 34, "uiui", "hc78h");
$otherarray = array("zozo", 78);
$newarray = array($anarray, $otherarray).
now, $newarray[0] contains an array that contains as element 0 the value "1", as element 1 the value "34" etc.
that means:
$newarray[0][0] contains "1",
$newarray[0][1] contains "34,
$newarray[1][1] contains "78" and so on.
[][] means two dimensions.
hope this helps