It’s just Google’s world and we’re all living in it. And now that’s a mobile-first world, Google’s rewriting the rules of the internet. Again. Google recently announced that it will prioritize mobile-first indexes over desktop indexes. If you are wondering what that means, then here’s a translation in plain English: Google will use the mobile version of a site’s content to rank pages from that site, even when you are searching from a desktop.

To refresh your SEO jargon, a search engine index is a collection of pages and documents that a search engine discovers through “crawling the web” through links. Google is the ultimate search engine (sorry, Bing) and it primarily uses a desktop browser to do that. But that’s all changing. As mobile search share continues to grow, the move is a smart one. And Google has given website owners a heads-up that these changes are coming. Not soon, but soon enough. (A few months, approximately).

So what does this mean for your website’s SEO? A few things:

One, many site owners will need to think carefully about infrastructure, data and organization. In order to keep the structured data for your pages in the search results for mobile, site owners will need to ensure the structured data appears on their mobile pages, too. Currently, mobile pages are much “lighter” than the information stored on a desktop page. In the future, site owners will need to treat mobile at least as equally—if not more so—than desktop pages; otherwise, a site owner could lose traffic for those keywords.

Two, site owners will have to move from mobile-friendly to mobile-first design to ensure that pages are serving the correct content. You may need to think carefully about a redesign and infrastructure overhaul to accommodate the switch. However, Google says it will not penalize you for not having a mobile website. If you only have a desktop site, they’ll continue to index your desktop site, even if you are searching on a mobile device.

Third and finally, there is a bright side for some: you may not have to do much at all. Websites with responsive design should be just fine with the mobile-first announcement. If Google recommends a responsive approach to your website—in which the content is the same on a page-by-page basis from your desktop to your mobile site—then you should heed their advice. Google has already mentioned that content not deemed mobile-friendly will not rank as well. That remains the case with this new index. In order to insure that your website stays SEO healthy as we enter a mobile-first world, be sure to look under the hood of your website to prepare for the major change. Otherwise, your website—and business—will suffer. Focus on maintaining a good user experience across all platforms, and you should be fine.