Array:Array is group of homogeneous data type object.The size of Array is fixed and array is strong data type.
int[]A=new int[6]{1,2,3,4,5,6}
Collection: Collection is group of heterogeneous data type object.The size of collection is not fixed and it contains the generic data type.
Collection=new Collection{Ram,Shyam}
List:List is Group of data type object
list=new list
where t is data type