Think of an array as a row of mailboxes.
We'll start with box #1, and let's say there are 10 of them.
To initialize the array,
Dim Mailboxes(10) as integer
This gives you 10 numbers you can associate with those mailboxes.
The real power comes with User Defined Types and Arrays.
Keeping that number doesn't do much for you to identify those mailboxes. So let's expand it a bit.
type mailbox_data
name as string
address as string
endtype
Dim Mailboxes(10) as mailbox_data
Now you can put the person's name and address in the fields associated with that mailbox.
Mailbox(1).name = "Robin Hood"
Mailbox(1).address = "4010 Marion Way"
Mailbox(2).name = "Little John"
Mailbox(2).address = "211 Frier Court"
Using for next loops, or counters you have a lot of power to work with.
for x = 1 to 10
print "Name " + Mailbox(x).name
print "Address " + Mailbox(x).address
next x
You don't have to use only strings in User Defined Types either. Those variables can be any data type. Integers, Floats, Bytes, anything.
Hope that helps a little.