I've Nissan Rouge SL 2015 with 18 inch wheel size. I want to buy steel wheels. When I look for options on Costco website it shows me Hubcentric and OEM Compatible. I'm not sure what's the significance of it. I searched online but could not come to any conclusion. Which one is better for the vehicle?
Hub-centric means that the center bore of the wheel (the hole you see in the middle) matches with the center bore size of the wheel hubs on your car. It's good to get a hub-centric wheel, as it helps center the wheel on the hub to prevent vibrations from imbalance.
What Costco means by "OEM compatible" means that the wheel will fit your car, however it is not hub-centric. Sometimes these wheels are called "lug-centric". If you click on the "More details" button, you'll notice that the center bore size is larger. Many aftermarket wheels have large bore sizes so that they'll fit on different makes and models of cars. In order to make these wheels hub-centric, you'll need to get hub-centric rings to fill the gap from the larger center bore. This is what they look like:
If you can find wheels that are hub-centric for your car, then by all means, buy those ones. You may want to look up the center bore size for your hubs to confirm this first. If you can't find the right size, then as mentioned, you can still fit wheels with larger center-bores; just make sure you get some hub-centric rings as well.
Further reading: ThoughtCo - Hub-Centric vs. Lug-Centric Wheels