Anyone care to explain to me how the integrated Sync feature works?

Ok, so i have an issue that was minor relatively speaking. Its finally came to the point of getting rid of it (now that i know whats actually causing it, sorta).

The sync feature. I like it - id love to use it, but in a specific way which escapes me. Let me explain.

I have 3 pc's i use currently. My main pc, my backup pc, and my laptop.

They have sequentially worse hardware and a few settings altered between the 3. I kept finding out I had no thumbnails on my main pc for example, even though it was toggled on it system>advanced. A quick toggle off and back on fixes it every time.

Now my laptop for example had this toggled off along with everything else in the "aesthetic" category in order for performance to be paramount. I also noticed in any win10 vm i ran it would always get a desktop theme synced but it always seemed to be from one of my other 2 pc's, never my main pc.

Now theyre all logged into the same microsoft account so heres what i need to know/what i want to happen.

1) does microsoft onedrive have to be installed and running for this to work properly for starters?

2) how would I set up the toggles if I want everything from my main PC to sync to the other 2 machines, but no changes made on the other 2 machines to sync back to my main PC or eachother?

Thanks for any insight, google bore no fruit. Article after article saying "turn it on here" or "turn it off here" and that was the extent of that.

Thank you for the reply! Good to know it does not require onedrive.

Now what do I toggle on the pc itself to ensure it can get settings from my main pc, but not upload them to the cloud? Do I just turn off syncing entirely? Or would that prevent it from getting settings from my main pc?

Keep on syncing but turn off the toggles below it on the non main PCs? Or is it both ways or nothing?

ok, perhaps im too dense. Or too used to dropbox lol.

Im sorta not following.

Is it bi directional?

If I turn on syncing on my main pc, then turn it on with my backup pc, my backup pc will get my main pc's settings due to them being in the cloud yes?

Now what happens if I change something on the backup pc? Does it then change it on the main pc?

Im trying to get different types of things synced on different pc's.

As an example - lets say I want to sync everything but my themes across all pc's Do i toggle on Sync settings and then toggle on everything BUT themes on all pc's?

and are you sure it doesnt require onedrive, as I have it uninstalled yet MS says it saves to "onedrive"

im not stupid in the slightest, but thi sis sure making me feel that way lol

ok, im gonna look through that tutorial. What I basically want is a starting template for any pc i should install/sign in on. But certain things not synced ever.

What i dont want is that if i ever change said things from the "starting template" on my backup pc for them to effect my main pc.

for now i turned them all off. deleted all settings from all pc's from the microsoft page. Turned everything back on for my main pc. Now i just have to figure out how to treat the backup pc and laptop so that they take the settings I want, but it isnt re uploaded and tossed back to my main pc.

Im probably misintrepreting something thats really simple. If its done in real time i can simply test it via one means or another but im unsure if thats the case. Anyhow let me look at the tutorial and thank you to both of you for assaulting my thick skull on this one.

Well i think I found part of my issue. I ran the microsoft accounts troubleshooter and it says cannot connect to the sync service.

I swear I spend more time getting my pcs running proper than actually using them :P

with a toddler and infant its an exercise in frustration let me teeeeeeeell you lol.