QUOTE: ‘To make our results more useful, we’ve begun experiments to make our index mobile-first. Although our search index will continue to be a single index of websites and apps, our algorithms will eventually primarily use the mobile version of a site’s content to rank pages from that site, to understand structured data, and to show snippets from those pages in our results. Of course, while our index will be built from mobile documents, we’re going to continue to build a great search experience for all users, whether they come from mobile or desktop devices.
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.
When referring to the homepage, a trailing slash after the hostname is optional since it leads to the same content ("https://example.com/" is the same as "https://example.com"). For the path and filename, a trailing slash would be seen as a different URL (signaling either a file or a directory), for example, "https://example.com/fish" is not the same as "https://example.com/fish/".
Search engines may penalize sites they discover using black or grey hat methods, either by reducing their rankings or eliminating their listings from their databases altogether. Such penalties can be applied either automatically by the search engines' algorithms, or by a manual site review. One example was the February 2006 Google removal of both BMW Germany and Ricoh Germany for use of deceptive practices.[54] Both companies, however, quickly apologized, fixed the offending pages, and were restored to Google's search engine results page.[55]
Robots.txt is not an appropriate or effective way of blocking sensitive or confidential material. It only instructs well-behaved crawlers that the pages are not for them, but it does not prevent your server from delivering those pages to a browser that requests them. One reason is that search engines could still reference the URLs you block (showing just the URL, no title or snippet) if there happen to be links to those URLs somewhere on the Internet (like referrer logs). Also, non-compliant or rogue search engines that don't acknowledge the Robots Exclusion Standard could disobey the instructions of your robots.txt. Finally, a curious user could examine the directories or subdirectories in your robots.txt file and guess the URL of the content that you don't want seen.
Smartphone - In this document, "mobile" or “mobile devices" refers to smartphones, such as devices running Android, iPhone, or Windows Phone. Mobile browsers are similar to desktop browsers in that they can render a broad set of the HTML5 specification, although their screen size is smaller and in almost all cases their default orientation is vertical.
In short, nobody is going to advise you to create a poor UX, on purpose, in light of Google’s algorithms and human quality raters who are showing an obvious interest in this stuff. Google is rating mobile sites on what it classes is frustrating UX – although on certain levels what Google classes as ‘UX’ might be quite far apart from what a UX professional is familiar with in the same ways as Google’s mobile rating tools differ from, for instance,  W3c Mobile testing tools.

At first glance, the Ads or SC appear to be MC. Some users may interact with Ads or SC, believing that the Ads or SC is the MC.Ads appear to be SC (links) where the user would expect that clicking the link will take them to another page within the same website, but actually take them to a different website. Some users may feel surprised or confused when clicking SC or links that go to a page on a completely different website.
A satisfying UX is can help your rankings, with second-order factors taken into consideration. A poor UX can seriously impact your human-reviewed rating, at least. Google’s punishing algorithms probably class pages as something akin to a poor UX if they meet certain detectable criteria e.g. lack of reputation or old-school SEO stuff like keyword stuffing a site.
QUOTE: “Duplicated content is often not manipulative and is commonplace on many websites and often free from malicious intent. Copied content can often be penalised algorithmically or manually. Duplicate content is not penalised, but this is often not an optimal set-up for pages, either. Be VERY careful ‘spinning’ ‘copied’ text to make it unique!” Shaun Anderson, Hobo, 2018

Google is looking for a “website that is well cared for and maintained” so you need to keep content management systems updated, check for broken image links and HTML links. If you create a frustrating user experience through sloppy website maintenance – expect that to be reflected in some way with a lower quality rating. Google Panda October 2014 went for e-commerce pages that were optimised ‘the old way’ and are now classed as ‘thin content’.
Google, in many instances, would rather send long-tail search traffic, like users using mobile VOICE SEARCH, for instance, to high-quality pages ABOUT a concept/topic that explains relationships and connections between relevant sub-topics FIRST, rather than to only send that traffic to low-quality pages just because they have the exact phrase on the page.
Write a description that would both inform and interest users if they saw your description meta tag as a snippet in a search result. While there's no minimal or maximal length for the text in a description meta tag, we recommend making sure that it's long enough to be fully shown in Search (note that users may see different sized snippets depending on how and where they search), and contains all the relevant information users would need to determine whether the page will be useful and relevant to them.
Domain authority is an important ranking phenomenon in Google. Nobody knows exactly how Google calculates, ranks and rates the popularity, reputation, intent or trust of a website, outside of Google, but when I write about domain authority I am generally thinking of sites that are popular, reputable and trusted – all of which can be faked, of course.

A poor 404 page and user interaction with it, can only lead to a ‘poor user experience’ signal at Google’s end, for a number of reasons. I will highlight a poor 404 page in my audits and actually programmatically look for signs of this issue when I scan a site. I don’t know if Google looks at your site that way to rate it e.g. algorithmically determines if you have a good 404 page – or if it is a UX factor, something to be taken into consideration further down the line – or purely to get you thinking about 404 pages (in general) to help prevent Google wasting resources indexing crud pages and presenting poor results to searchers. I think rather that any rating would be a second order scoring including data from user activity on the SERPs – stuff we as SEO can’t see.
If you are improving user experience by focusing primarily on the quality of the MC of your pages and avoiding – even removing – old-school SEO techniques – those certainly are positive steps to getting more traffic from Google in 2019 – and the type of content performance Google rewards is in the end largely at least about a satisfying user experience.
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]
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.
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.
While Google never sells better ranking in our search results, several other search engines combine pay-per-click or pay-for-inclusion results with their regular web search results. Some SEOs will promise to rank you highly in search engines, but place you in the advertising section rather than in the search results. A few SEOs will even change their bid prices in real time to create the illusion that they "control" other search engines and can place themselves in the slot of their choice. This scam doesn't work with Google because our advertising is clearly labeled and separated from our search results, but be sure to ask any SEO you're considering which fees go toward permanent inclusion and which apply toward temporary advertising.
Some search engines have also reached out to the SEO industry, and are frequent sponsors and guests at SEO conferences, webchats, and seminars. Major search engines provide information and guidelines to help with website optimization.[18][19] Google has a Sitemaps program to help webmasters learn if Google is having any problems indexing their website and also provides data on Google traffic to the website.[20] Bing Webmaster Tools provides a way for webmasters to submit a sitemap and web feeds, allows users to determine the "crawl rate", and track the web pages index status.
The errors in technical SEO are often not obvious, and therefore one of the most popular. Mistakes in robots.txt and 404 pages, pagination and canonical URLs, hreflang tags and 301 redirects, http vs https and www vs non www versions: each of them can seriously spoil all efforts to promote the site. One quality SEO website analysis is enough to solve all the main problems in this part forever.
Webmasters and content providers began optimizing websites for search engines in the mid-1990s, as the first search engines were cataloging the early Web. Initially, all webmasters only needed to submit the address of a page, or URL, to the various engines which would send a "spider" to "crawl" that page, extract links to other pages from it, and return information found on the page to be indexed.[5] The process involves a search engine spider downloading a page and storing it on the search engine's own server. A second program, known as an indexer, extracts information about the page, such as the words it contains, where they are located, and any weight for specific words, as well as all links the page contains. All of this information is then placed into a scheduler for crawling at a later date.
Early versions of search algorithms relied on webmaster-provided information such as the keyword meta tag or index files in engines like ALIWEB. Meta tags provide a guide to each page's content. Using metadata to index pages was found to be less than reliable, however, because the webmaster's choice of keywords in the meta tag could potentially be an inaccurate representation of the site's actual content. Inaccurate, incomplete, and inconsistent data in meta tags could and did cause pages to rank for irrelevant searches.[10][dubious – discuss] Web content providers also manipulated some attributes within the HTML source of a page in an attempt to rank well in search engines.[11] By 1997, search engine designers recognized that webmasters were making efforts to rank well in their search engine, and that some webmasters were even manipulating their rankings in search results by stuffing pages with excessive or irrelevant keywords. Early search engines, such as Altavista and Infoseek, adjusted their algorithms to prevent webmasters from manipulating rankings.[12]
QUOTE: “(Google Panda) measures the quality of a site pretty much by looking at the vast majority of the pages at least. But essentially allows us to take quality of the whole site into account when ranking pages from that particular site and adjust the ranking accordingly for the pages. So essentially, if you want a blunt answer, it will not devalue, it will actually demote. Basically, we figured that site is trying to game our systems, and unfortunately, successfully. So we will adjust the rank. We will push the site back just to make sure that it’s not working anymore.”  Gary Illyes – Search Engine Land

Sometimes, Google turns up the dial on demands on ‘quality’, and if your site falls short, a website traffic crunch is assured. Some sites invite problems ignoring Google’s ‘rules’ and some sites inadvertently introduce technical problems to their site after the date of a major algorithm update and are then impacted negatively by later refreshes of the algorithm.

Important: The Lowest rating is appropriate if all or almost all of the MC on the page is copied with little or no time, effort, expertise, manual curation, or added value for users. Such pages should be rated Lowest, even if the page assigns credit for the content to another source. Important: The Lowest rating is appropriate if all or almost all of the MC on the page is copied with little or no time, effort, expertise, manual curation, or added value for users. Such pages should be rated Lowest, even if the page assigns credit for the content to another source.

A lot of optimisation techniques that are in the short term effective at boosting a site’s position in Google are against Google’s guidelines. For example, many links that may have once promoted you to the top of Google, may, in fact, today be hurting your site and its ability to rank high in Google. Keyword stuffing might be holding your page back. You must be smart, and cautious, when it comes to building links to your site in a manner that Google *hopefully* won’t have too much trouble with, in the FUTURE. Because they will punish you in the future.
******” Quote from Google: One other specific piece of guidance we’ve offered is that low-quality content on some parts of a website can impact the whole site’s rankings, and thus removing low-quality pages, merging or improving the content of individual shallow pages into more useful pages, or moving low-quality pages to a different domain could eventually help the rankings of your higher-quality content. GOOGLE ******

There are a lot of definitions of SEO (spelled Search engine optimisation in the UK, Australia and New Zealand, or search engine optimization in the United States and Canada) but organic SEO in 2019 is still mostly about getting free traffic from Google, the most popular search engine in the world (and almost the only game in town in the UK in 2019):
We expect advertisements to be visible. However, you should not let the advertisements distract users or prevent them from consuming the site content. For example, advertisements, supplement contents, or interstitial pages (pages displayed before or after the content you are expecting) that make it difficult to use the website. Learn more about this topic.38
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.
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.
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.
By relying so much on factors such as keyword density which were exclusively within a webmaster's control, early search engines suffered from abuse and ranking manipulation. To provide better results to their users, search engines had to adapt to ensure their results pages showed the most relevant search results, rather than unrelated pages stuffed with numerous keywords by unscrupulous webmasters. This meant moving away from heavy reliance on term density to a more holistic process for scoring semantic signals.[13] Since the success and popularity of a search engine is determined by its ability to produce the most relevant results to any given search, poor quality or irrelevant search results could lead users to find other search sources. Search engines responded by developing more complex ranking algorithms, taking into account additional factors that were more difficult for webmasters to manipulate. In 2005, an annual conference, AIRWeb (Adversarial Information Retrieval on the Web), was created to bring together practitioners and researchers concerned with search engine optimization and related topics.[14]
Try and get links within page text pointing to your site with relevant, or at least, natural looking, keywords in the text link – not, for instance, in blogrolls or site-wide links. Try to ensure the links are not obviously “machine generated” e.g. site-wide links on forums or directories. Get links from pages, that in turn, have a lot of links to them, and you will soon see benefits.

QUOTE: “I’ve got a slide here where I show I think 8 different URLs you know every single one of these URLs could return completely different content in practice we as humans whenever we look at ‘www.example.com’ or just regular ‘example.com’ or example.com/index or example.com/home.asp we think of it as the same page and in practice it usually is the same page so technically it doesn’t have to be but almost always web servers will return the same content for like these 8 different versions of the URL so that can cause a lot of problems in search engines if rather than having your backlinks all go to one page instead it’s split between (the versions) and it’s a really big headache….how do people fix this well …. the canonical link element” Matt Cutts, Google
Users will occasionally come to a page that doesn't exist on your site, either by following a broken link or typing in the wrong URL. Having a custom 404 page30 that kindly guides users back to a working page on your site can greatly improve a user's experience. Your 404 page should probably have a link back to your root page and could also provide links to popular or related content on your site. You can use Google Search Console to find the sources of URLs causing "not found" errors31.