There are three types of crawling, all of which provide useful data. Internet-wide crawlers are for large-scale link indexing. It's a complicated and often expensive process but, as with social listening, the goal is for SEO experts, business analysts, and entrepreneurs to be able to map how websites link to one another and extrapolate larger SEO trends and growth opportunities. Crawling tools generally do this with automated bots continuously scanning the web. As is the case with most of these SEO tools, many businesses use internal reporting features in tandem with integrated business intelligence (BI) tools to identify even deeper data insights. Ahrefs and Majestic are the two clear leaders in this type of crawling. They have invested more than a decade's worth of time and resources, compiling and indexing millions and billions, respectively, of crawled domains and pages.
It is important you spread all that real ‘PageRank’ – or link equity – to your sales keyword / phrase rich sales pages, and as much remains to the rest of the site pages, so Google does not ‘demote’ pages into oblivion –  or ‘supplemental results’ as we old timers knew them back in the day. Again – this is slightly old school – but it gets me by, even today.

Comparing your Google Analytics data side by side with the dates of official algorithm updates is useful in diagnosing a site health issue or traffic drop. In the above example, a new client thought it was a switch to HTTPS and server downtime that caused the drop when it was actually the May 6, 2015, Google Quality Algorithm (originally called Phantom 2 in some circles) that caused the sudden drop in organic traffic – and the problem was probably compounded by unnatural linking practices. (This client did eventually receive a penalty for unnatural links when they ignored our advice to clean up).
For example, within the HubSpot Blogging App, users will find as-you-type SEO suggestions. This helpful inclusion serves as a checklist for content creators of all skill levels. HubSpot customers also have access to the Page Performance App, Sources Report, and the Keyword App. The HubSpot Marketing Platform will provide you with the tools you need to research keywords, monitor their performance, track organic search growth, and diagnose pages that may not be fully optimized.
What would be the purpose of/reason for moving back to a different url? If its been a few years, I’d leave it alone unless you watched everything decline since moving to the main url. Moving the forum to a new url now would probably be a bit chaotic, not only for your main url but for the forum itself…. Only reason I could imagine myself moving the forum in this scenario would be if all those links were really awful and unrelated to the url it currently sits on…
Description meta tags are important because Google might use them as snippets for your pages. Note that we say "might" because Google may choose to use a relevant section of your page's visible text if it does a good job of matching up with a user's query. Adding description meta tags to each of your pages is always a good practice in case Google cannot find a good selection of text to use in the snippet. The Webmaster Central Blog has informative posts on improving snippets with better description meta tags18 and better snippets for your users19. We also have a handy Help Center article on how to create good titles and snippets20.
In 1998, two graduate students at Stanford University, Larry Page and Sergey Brin, developed "Backrub", a search engine that relied on a mathematical algorithm to rate the prominence of web pages. The number calculated by the algorithm, PageRank, is a function of the quantity and strength of inbound links.[22] PageRank estimates the likelihood that a given page will be reached by a web user who randomly surfs the web, and follows links from one page to another. In effect, this means that some links are stronger than others, as a higher PageRank page is more likely to be reached by the random web surfer.
A navigational page is a simple page on your site that displays the structure of your website, and usually consists of a hierarchical listing of the pages on your site. Visitors may visit this page if they are having problems finding pages on your site. While search engines will also visit this page, getting good crawl coverage of the pages on your site, it's mainly aimed at human visitors.
SEO stands for ‘Search Engine Optimization’. It’s the practice of optimizing your web pages to make them reach a high position in the search results of Google or other search engines. SEO focuses on improving the rankings in the organic – aka non paid – search results. If you have a website and you want to get more traffic, it should be part of your marketing efforts. Here, I’ll explain what SEO is and how we approach it at Yoast.
Now, some buckets are worth more than others, and the three main buckets that you need to be aware of for search rankings are quality, trust and authority. So quality: what Google is trying to measure when they’re trying to figure out what sites should rank is offering something valuable or unique or interesting to googles searchers. For example: good content—if you are selling t-shirts and you are using the same description that every other t-shirt seller is using on their website then you are not offering anything unique to Google’s searchers.
In 2007, Google announced a campaign against paid links that transfer PageRank.[30] On June 15, 2009, Google disclosed that they had taken measures to mitigate the effects of PageRank sculpting by use of the nofollow attribute on links. Matt Cutts, a well-known software engineer at Google, announced that Google Bot would no longer treat any nofollow links, in the same way, to prevent SEO service providers from using nofollow for PageRank sculpting.[31] As a result of this change the usage of nofollow led to evaporation of PageRank. In order to avoid the above, SEO engineers developed alternative techniques that replace nofollowed tags with obfuscated JavaScript and thus permit PageRank sculpting. Additionally several solutions have been suggested that include the usage of iframes, Flash and JavaScript.[32]