Based on your comments from the blog and the poll, it looks like you are requesting some information and guidance on how to move your arms during the freestyle stroke.
So, here we go.
Freestyle is what you would call an asymmetric swimming style.
Well, asymmetric is a strong word, but almost.
What do I mean by this?
Imagine you are laying on the floor on your stomach.
(Note: Freestyle is not performed on your stomach, but rather on your sides. This is only for visualization purposes.).
Facedown and place your arms alongside your body.
Extend one arm along the floor to the front of your head.
Now you have one arm laying on the floor in front of your head and one at your side.
This is quite asymmetric, isn't it?
As opposed to symmetric swimming style where both sides of your body do the same things, so both arms would move from the position along side of your body to "in front of your head" at the same time.
Now that we have that covered, let's focus on freestyle swimming.
It is very similar to what I have described above with your body being on the floor face down with one arm extended in front of your head and one arm alongside your body.
Keep one arm extended, palm facing down and now roll on the hip which is on the side that your arm is extended.
So you are now laying on your side with the bottom arm extended and top arm resting on your hip.
Just imagine you are in the same position in the water and start rotating your straight arms at the same time.
So the sequence would be to rotate your upper hip towards the floor, your upper arm towards the front and then when your upper arm is about halfway between your hip and the front of your body, start moving your front arm towards your hip.
Like a very slow windmill where one arm always has a bit of a head lead.
If someone tells you that you should start the freestyle stroke only when your back arm reaches/touches your front arm, they are wrong as that is not how to properly swim freestyle.
This type of freestyle swimming is called the catch-up drill (one arm catches the other) and is only used to fine-tune your arm movements in a slower speed.
So, do not let your arms catch each other, but do not allow them to be the exact opposite of each other either.
As I mentioned earlier, the back arm is not a mirror image of the front one, however, it is also not a full-blown catch-up.
The reason why the arms are not fully opposite of each other is lack of support.
If you start moving your back arm up and front arm down, you will be in a cross-like position with your arms at one point.
Then what happens if you need to take a breath?
You cannot as you do not have your front arm's support in front.
Hence you need to wait with the front arm a little in the extended (aka glide) position and let the back arm start the motion sooner.
Here is a video that can help to explain it visually.
Chances are though, that it is not the arms that you should focus on first.
I'd suggest starting with your body and head position and then move onto mastering the feat of moving your freestyle arms.
Once you have the windmill arm rotation going, you can focus on other things like how to catch more water (how to move your arm/hand through the water to go faster) or how to position your head while swimming freestyle, what to do with your hips.
Or finally what to do with your arms when they are above the water which I will discuss in my next posts, so stay tuned and keep swimming.