Selected answers from the Dumb SEO Questions Facebook & G+ community.
Michael Martinez: Not exactly. It`s just that sites are ranked on the basis of how they are crawled. Most sites are now crawled by at least the mobile Googlebot, although the desktop Googlebot may still fetch pages from them.
Some sites have not yet been moved over to mobile crawling. Google had scheduled to move the rest of the index to mobile-first crawling by September but that deadline is now in question, so it sounds like some of their programming has been slowed down.
Nathan Nikolay Gaidy: Michael Martinez So two different rankings and two different bots?
Michael Martinez: Nathan Nikolay Gaidy Two different bots but only one version of your site is indexed. That one version of the site will be used by all selection and ranking/scoring algorithms.
Nathan Nikolay Gaidy: Michael Martinez Wait what?! So if my website is mobile and desktop friendly The mobile version will be indexed and the desktop will not?!
Michael Martinez: Nathan Nikolay Gaidy Assuming you have two versions of your site and every page on the desktop version has a mobile counterpart, yes.
If you have two versions of your site and more desktop pages than mobile pages, or not all desktop pages have mobile counterparts, then Google may decide to index pages from both versions (but they make no guarantees).
If your site is responsive then there is only one site for Google to index and it won`t matter which crawler they use.
Nathan Nikolay Gaidy: Dreamweaver creates multiple versions of the same page? https://helpx.adobe.com/dreamwe.../using/device-preview.html
Michael Martinez: Every site has many ranking scores. But there is only one set of ranking algorithms and they work with whatever the crawlers hand them.
A site will be primarily crawled and indexed through only one format, mobile or desktop.