first, let me clarify...... "tow time" = TWO TIMES (@Danyfirex explained it though I thought you might still miss that finer point. I've been married to a Russian woman for 20 years and I'm now living in Ecuador, so I'm used to reading and speaking 'non-native', though not everyone is)
on the array - glad my crude diagram helped (again, living with and teaching technology to non-native English speakers has given me some 'talent' for KISS training......
To your question - it could be that you would want to create an array like that, though what you are doing in your example is creating an array of folder names to a path - not at all what I would call 'common' use, but again, you could - after all, it is just "words on a page" (as I like to call it - others call it "data"....) - and while those 'words' mean something to someone, part of your task as a programmer is to forget about what those things do/say/spell/mean and simply manipulate them around as you need them. (this is probably a different concept for you, so don't worry if you don't grasp it first time, but the closer you get to separating yourself from the 'meaning' of what is moving around, the faster you can learn what arrays (and database segments, etc.) can do for you.
They are just storage locations for 'words' (or pictures, or....... - data!)
keeping my piece-o-paper vision handy, look at arrays another way - think of a school locker, or perhaps a row of post office boxes, stacked on top of each other. For our example, think of ONE row only! (either vertical or horizontal, though typically arrays are thought of in a vertical stack - like the piece of paper....) Arrays can grow to many rows and columns (if you have dealt with spreadsheets, these terms are easier to understand), but we are talking about a simple array, one 'stack' (or column if you prefer...)
Now, getting back to your example of 'folder1folder2folder3 - if what you are doing is breaking up pathnames, then you seem to be getting the idea very well. You break the data by whatever delimiter you can (which sometimes is a or comma, or even X characters - whatever it is...) and you put the bits, one per each location, into each 'storage box' (or locker, or 'stack location' - again terms are not important other than your understanding).
So, in your example, if you have an array called $pathtofolder and you did a split of the pathname 'folder1folder2folder3 by , you would have
$pathtofolder[0] = 3 <<====== this is how AutoIt handles things most of the time (it is a bit confusing because it is not always done this way - see below)
$pathtofolder[1] = folder1
$pathtofolder[2] = folder2
$pathtofolder[3] = folder3
So, yes, you are on the right track, I think.
Now, I won't go into detail on the [0] array bit - AutoIt handles it in various ways and you should read the docs for some details on when/why/how it might change, but know that 1) you have control over how it works and 2) AutoIt gives variations that are very powerful when used correctly (i.e., I was very confused at first, but after a few days of messing with it, I have grown to really like the use of the [0] array bit and think it is quite a handy tool).
Keep studying on arrays and think of stacks of boxes (or whatever) and then you can put something in each one, as/where you like. As long as you have some way to keep track of where that thing is, you can easily go get it, use it and put it back (changed or not - your decision) in the same place, or add it to another box, throw it away, etc. (i.e., manipulate the data as you like)
Hope this helps.