ARRAY LIST 1) It belongs to system.collection namespace 2)It consists of elements of different data type 3)We can increase or decrease the size of array list by using add or remove methods 4)It can only exist in single dimensionARRAY 1)It belongs to system namespace 2)It consists of elements of same datatype 3)We cannot change the size of array 4)It can be multidimensional example of array list: Dim myarray as new arraylist example of array: Dim myarray(20) As Integer

Array contain a similar data type and array size is fixed i.e 
dynamically its size can't be changed.
but arraylist can store more then one data type and its size
can be changed dynamically.
one major difference is that,array used to store primitive
data type(i.e. int,char etc) while arraylist is used to
store objects.

Array is fixed length,array-list is growing array(means 
they have no fixed length , if u add more the size 
arraylist size incress and vise versa)
seond one:
if add and remove the elements in the middle takes more 
time by using arrylist in that time use linkedlist
 arrylist is good  for retiveing the elements in specific 
position
  arraylist is faster than linkedlist for random accesing 
of elemnets