Google and Bing use a crawler (Googlebot and Bingbot) that spiders the web looking for new links to find. These bots might find a link to your homepage somewhere on the web and then crawl and index the pages of your site if all your pages are linked together. If your website has an XML sitemap, for instance, Google will use that to include that content in its index. An XML sitemap is INCLUSIVE, not EXCLUSIVE.  Google will crawl and index every single page on your site – even pages out with an XML sitemap.

The world is mobile today. Most people are searching on Google using a mobile device. The desktop version of a site might be difficult to view and use on a mobile device. As a result, having a mobile ready site is critical to your online presence. In fact, starting in late 2016, Google has begun experiments to primarily use the mobile version of a site's content42 for ranking, parsing structured data, and generating snippets.
I prefer simple SEO techniques and ones that can be measured in some way. I have never just wanted to rank for competitive terms; I have always wanted to understand at least some of the reasons why a page ranked for these key phrases. I try to create a good user experience for humans AND search engines. If you make high-quality text content relevant and suitable for both these audiences, you’ll more than likely find success in organic listings and you might not ever need to get into the technical side of things, like redirects and search engine friendly URLs.
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.
QUOTE: “Google will now begin encrypting searches that people do by default, if they are logged into already through a secure connection. The change to SSL search also means that sites people visit after clicking on results at Google will no longer receive “referrer” data that reveals what those people searched for, except in the case of ads.
Search engines use complex mathematical algorithms to interpret which websites a user seeks. In this diagram, if each bubble represents a website, programs sometimes called spiders examine which sites link to which other sites, with arrows representing these links. Websites getting more inbound links, or stronger links, are presumed to be more important and what the user is searching for. In this example, since website B is the recipient of numerous inbound links, it ranks more highly in a web search. And the links "carry through", such that website C, even though it only has one inbound link, has an inbound link from a highly popular site (B) while site E does not. Note: Percentages are rounded.
QUOTE: “How do I move from one domain to another domain and try to preserve the rankings as best as possible?…do a 301 permanent redirect to the new location (assuming that you’re you’re moving for all time and eternity so this is the good case for a permanent or 301 redirect if you were planning to undo this later or it’s temporary then you’d use a 302 redirect)…. search engines should be able to follow the trail of all the 301 redirects” Matt Cutts, Google
When using the Keyword Explorer, Ahrefs will also produce the "parent topic" of the keyword you looked up, as you can see in the screenshot above, underneath the Keyword Difficulty meter. A keyword's parent topic is a broader keyword with higher search volume than your intended keyword, but likely has the same audience and ranking potential -- giving you more a valuable SEO opportunity when optimizing a particular blog post or webpage.
Structured data21 is code that you can add to your sites' pages to describe your content to search engines, so they can better understand what's on your pages. Search engines can use this understanding to display your content in useful (and eye-catching!) ways in search results. That, in turn, can help you attract just the right kind of customers for your business.
An SEO technique is considered white hat if it conforms to the search engines' guidelines and involves no deception. As the search engine guidelines[18][19][52] are not written as a series of rules or commandments, this is an important distinction to note. White hat SEO is not just about following guidelines but is about ensuring that the content a search engine indexes and subsequently ranks is the same content a user will see. White hat advice is generally summed up as creating content for users, not for search engines, and then making that content easily accessible to the online "spider" algorithms, rather than attempting to trick the algorithm from its intended purpose. White hat SEO is in many ways similar to web development that promotes accessibility,[53] although the two are not identical.
QUOTE: “Ultimately, you just want to have a really great site people love. I know it sounds like a cliché, but almost [all of] what we are looking for is surely what users are looking for. A site with content that users love – let’s say they interact with content in some way – that will help you in ranking in general, not with Panda. Pruning is not a good idea because with Panda, I don’t think it will ever help mainly because you are very likely to get Panda penalized – Pandalized – because of low-quality content…content that’s actually ranking shouldn’t perhaps rank that well. Let’s say you figure out if you put 10,000 times the word “pony” on your page, you rank better for all queries. What Panda does is disregard the advantage you figure out, so you fall back where you started. I don’t think you are removing content from the site with potential to rank – you have the potential to go further down if you remove that content. I would spend resources on improving content, or, if you don’t have the means to save that content, just leave it there. Ultimately people want good sites. They don’t want empty pages and crappy content. Ultimately that’s your goal – it’s created for your users.” Gary Illyes, Google 2017
OBSERVATION – You can have the content and the links – but if your site falls short on even a single user satisfaction signal (even if it is picked up by the algorithm, and not a human reviewer) then your rankings for particular terms could collapse – OR – rankings can be held back – IF Google thinks your organisation, with its resources, or ‘reputation, should be delivering a better user experience to users.
When I think ‘Google-friendly’ these days – I think a website Google will rank top, if popular and accessible enough, and won’t drop like a f*&^ing stone for no apparent reason one day, even though I followed the Google SEO starter guide to the letter….. just because Google has found something it doesn’t like – or has classified my site as undesirable one day.
I think it makes sense to have unique content as much as possible on these pages but it’s not not going to like sync the whole website if you don’t do that we don’t penalize a website for having this kind of deep duplicate content and kind of going back to the first thing though with regards to doorway pages that is something I definitely look into to make sure that you’re not running into that so in particular if this is like all going to the same clinic and you’re creating all of these different landing pages that are essentially just funneling everyone to the same clinic then that could be seen as a doorway page or a set of doorway pages on our side and it could happen that the web spam team looks at that and says this is this is not okay you’re just trying to rank for all of these different variations of the keywords and the pages themselves are essentially all the same and they might go there and say we need to take a manual action and remove all these pages from search so that’s kind of one thing to watch out for in the sense that if they are all going to the same clinic then probably it makes sense to create some kind of a summary page instead whereas if these are going to two different businesses then of course that’s kind of a different situation it’s not it’s not a doorway page situation.”

QUOTE: “Another problem we were having was an issue with quality and this was particularly bad (we think of it as around 2008 2009 to 2011) we were getting lots of complaints about low-quality content and they were right. We were seeing the same low-quality thing but our relevance metrics kept going up and that’s because the low-quality pages can be very relevant. This is basically the definition of a content farm in our in our vision of the world so we thought we were doing great our numbers were saying we were doing great and we were delivering a terrible user experience and turned out we weren’t measuring what we needed to so what we ended up doing was defining an explicit quality metric which got directly at the issue of quality it’s not the same as relevance …. and it enabled us to develop quality related signals separate from relevant signals and really improve them independently so when the metrics missed something what ranking engineers need to do is fix the rating guidelines… or develop new metrics.” SMX West 2016 – How Google Works: A Google Ranking Engineer’s Story (VIDEO)

One common scam is the creation of "shadow" domains that funnel users to a site by using deceptive redirects. These shadow domains often will be owned by the SEO who claims to be working on a client's behalf. However, if the relationship sours, the SEO may point the domain to a different site, or even to a competitor's domain. If that happens, the client has paid to develop a competing site owned entirely by the SEO.

SEOptimer is a free SEO Audit Tool that will perform a detailed SEO Analysis across 100 website data points, and provide clear and actionable recommendations for steps you can take to improve your online presence and ultimately rank better in Search Engine Results. SEOptimer is ideal for website owners, website designers and digital agencies who want to improve their own sites or theirs of their clients.
Optimizing a website may involve editing its content, adding content, and modifying HTML and associated coding to both increase its relevance to specific keywords and remove barriers to the indexing activities of search engines like Google ,Yahoo etc.[citation needed] Promoting a site to increase the number of backlinks, or inbound links, is another SEO tactic. By May 2015, mobile search had surpassed desktop search.[3]
KISS does not mean boring web pages. You can create stunning sites with smashing graphics – but you should build these sites using simple techniques – HTML & CSS, for instance. If you are new to web design, avoid things like Flash and JavaScript, especially for elements like scrolling news tickers, etc. These elements work fine for TV – but only cause problems for website visitors.
QUOTE: “Medium pages achieve their purpose and have neither high nor low expertise, authoritativeness, and trustworthiness. However, Medium pages lack the characteristics that would support a higher quality rating. Occasionally, you will find a page with a mix of high and low quality characteristics. In those cases, the best page quality rating may be Medium.” Google Quality Evaluator Guidelines, 2017
Since heading tags typically make text contained in them larger than normal text on the page, this is a visual cue to users that this text is important and could help them understand something about the type of content underneath the heading text. Multiple heading sizes used in order create a hierarchical structure for your content, making it easier for users to navigate through your document.