what is a jagged array
for a start there are two types of arrays in c#
1) rectangular arrays
2) jagged arrays
rectangular arrays are of course rectangular arrays :-) wether single dimensional or multi dimensional all their elements length are equal
e.g
int[] arrSingle=new arrSingle[5];
int[,] arrTwoDimensional=new int[,] {{1,2,3},{1,2,3}}
jagged arrays are just arrays of arrays but when it comes to their shape their element length can vary
int[][] jaggedArray = new int[3][];
jaggedArray[0] = new int[] {1, 2, 3};
jaggedArray[1] = new int[] {1, 2, 3, 4, 5, 6};
jaggedArray[2] = new int[] {1, 2, 3, 4, 5, 6, 7, 8, 9};
thats all you need to know