My website has 500,000 pages, Ive submitted urls to my Google webmaster tools accountEvery week I check and the number of Urls indexed is slowly creeping up, the number of urls submitted is unchanged.30,000 URLs submitted15,672 URLs indexedDoes the 15,672 URLS indexed mean that of the 30,000 Ive submitted Google has so far indexed 15,672 or does it mean that 30,000 urls Ive submitted have been indexed and Google has independently crawled and indexed and additional 15,672 urls - so 45,672 urls indexedFor clarity:Go to Google Webmaster toolsSelect ResourceSelect CrawlSelect SitemapFor each sitemap it has a submitted and indexed columnSo it seems to indicate that a sitemap was submitted with x pages, but google has only indexed y so far. I wrote this question from memory about a situation i saw a couple of months ago, now I look at the site again it seems clearer what submitted and indexed are, but then the question is where do I see a count of pages that have been indexed but are not in the sitemaps submitted. After all I have only submitted 30,000 of 500,000 possible pages so any of the other 470,000 could  be indexed via google crawling for them independently.
In Google Webmaster tools is indexed Urls and subset or in addition to Submitted Urls
google;google search console
There are two sets of pages indexed within Google Search Console:Google Index > Index Status-- and --Crawl > SitemapsYou will find that these numbers are confusing. They represent two different things.If you are referring to any sitemap submitted (Crawl > Sitemaps) and the stats associated with it versus indexed pages (Google Index > Index Status), then yes, these are two separate processes and what you see on the sitemap page should not concern you.The pages indexed (Google Index > Index Status) refers to pages indexed (Duh!) no matter how they are found either by crawling and following links or using the sitemap.On the flip side, the sitemap page (Crawl > Sitemaps) is another whole process of auditing the sitemap for pages that are indexed. This goes in fits and starts and is often nothing more than a rough count when Google stopped last.When you look at these numbers (Crawl > Sitemaps), the Submitted number is the number of pages referenced within the sitemap, and the Indexed number refers to the number of pages Google knows it has indexed from the sitemap so far. This is usually confusing because people think it is the total number of pages indexed, but it is not. The indexed pages (Google Index > Index Status) represents the number of pages Google has indexed.Whereas the pages indexed (Google Index > Index Status) is semi-live data, the sitemap (Crawl > Sitemaps) is not. It depends on an audit process which can continue to add pages to the count or start over at any point. Do not be alarmed if you see this number go down even to near 0. This means a new fresh audit is beginning. In fact, this is a good thing!