I'm unsure if I understand your problem... so I'll try tp explain what arrays are:

Definition
An array is a collection of values of the same type

Usage
You need an array where ever you have to do something for more than 1 variable coz you can use a loop then. For example if you make a game and you want to move enemies, without arrays you'd have to do something like this:
Code:
Dim Enemy1
Dim Enemy2
Dim Enemy3
...
Enemy1.Move
Enemy2.Move
Enemy3.Move
If you instead use an array you can replace much code:
Code:
Dim Enemy(5)
...
Dim A as Long

For A = 0 to 5
   Enemy(A).Move
Next
See the difference? Another good thing is that you can change the size of an array at runtime:
Code:
Dim A() as long

ReDim A(10) 'Set a size
ReDim Preserve A(20) 'Make it bigger
ReDim Preserve A(5) 'and smaller...
(While preserve means that A does not lose the values already contained when resizing)