To avoid undesirable content in the search indexes, webmasters can instruct spiders not to crawl certain files or directories through the standard robots.txt file in the root directory of the domain. Additionally, a page can be explicitly excluded from a search engine's database by using a meta tag specific to robots (usually ). When a search engine visits a site, the robots.txt located in the root directory is the first file crawled. The robots.txt file is then parsed and will instruct the robot as to which pages are not to be crawled. As a search engine crawler may keep a cached copy of this file, it may on occasion crawl pages a webmaster does not wish crawled. Pages typically prevented from being crawled include login specific pages such as shopping carts and user-specific content such as search results from internal searches. In March 2007, Google warned webmasters that they should prevent indexing of internal search results because those pages are considered search spam.[47]
Search engine optimization (SEO) is often about making small modifications to parts of your website. When viewed individually, these changes might seem like incremental improvements, but when combined with other optimizations, they could have a noticeable impact on your site's user experience and performance in organic search results. You're likely already familiar with many of the topics in this guide, because they're essential ingredients for any web page, but you may not be making the most out of them.

Google WILL classify your site when it crawls and indexes your site – and this classification can have a DRASTIC effect on your rankings. It’s important for Google to work out WHAT YOUR ULTIMATE INTENT IS – do you want to be classified as a thin affiliate site made ‘just for Google’, a domain holding page or a small business website with a real purpose? Ensure you don’t confuse Google in any way by being explicit with all the signals you can – to show on your website you are a real business, and your INTENT is genuine – and even more important today – FOCUSED ON SATISFYING A VISITOR.
The basics of GOOD SEO hasn’t changed for years – though effectiveness of particular elements has certainly narrowed or changed in type of usefulness – you should still be focusing on building a simple site using VERY simple SEO best practices – don’t sweat the small stuff, while all-the-time paying attention to the important stuff  – add plenty of unique PAGE TITLES and plenty of new ORIGINAL CONTENT. Understand how Google SEES your website. CRAWL it, like Google does, with (for example) Screaming Frog SEO spider, and fix malformed links or things that result in server errors (500), broken links (400+) and unnecessary redirects (300+). Each page you want in Google should serve a 200 OK header message.
After a while, Google will know about your pages, and keep the ones it deems ‘useful’ – pages with original content, or pages with a lot of links to them. The rest will be de-indexed. Be careful – too many low-quality pages on your site will impact your overall site performance in Google. Google is on record talking about good and bad ratios of quality content to low-quality content.
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)
QUOTE: “The duration performance scores can be used in scoring resources and websites for search operations. The search operations may include scoring resources for search results, prioritizing the indexing of websites, suggesting resources or websites, protecting particular resources or websites from demotions, precluding particular resources or websites from promotions, or other appropriate search operations.” A Panda Patent on Website and Category Visit Durations
After a while, Google will know about your pages, and keep the ones it deems ‘useful’ – pages with original content, or pages with a lot of links to them. The rest will be de-indexed. Be careful – too many low-quality pages on your site will impact your overall site performance in Google. Google is on record talking about good and bad ratios of quality content to low-quality content.
QUOTE: “I think there is probably a misunderstanding that there’s this one site-wide number that Google keeps for all websites and that’s not the case.  We look at lots of different factors and there’s not just this one site-wide quality score that we look at. So we try to look at a variety of different signals that come together, some of them are per page, some of them are more per site, but it’s not the case where there’s one number and it comes from these five pages on your website.” John Mueller, Google
If you are just starting out, don’t think you can fool Google about everything all the time. Google has VERY probably seen your tactics before. So, it’s best to keep your plan simple. GET RELEVANT. GET REPUTABLE. Aim for a healthy, satisfying visitor experience. If you are just starting out – you may as well learn how to do it within Google’s Webmaster Guidelines first. Make a decision, early, if you are going to follow Google’s guidelines, or not, and stick to it. Don’t be caught in the middle with an important project. Do not always follow the herd.

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.
Good news for web designers, content managers and search engine optimisers! ” Google clearly states, “If the website feels inadequately updated and inadequately maintained for its purpose, the Low rating is probably warranted.” although does stipulate again its horses for courses…..if everybody else is crap, then you’ll still fly – not much of those SERPs about these days.
If you link out to irrelevant sites, Google may ignore the page, too – but again, it depends on the site in question. Who you link to, or HOW you link to, REALLY DOES MATTER – I expect Google to use your linking practices as a potential means by which to classify your site. Affiliate sites, for example, don’t do well in Google these days without some good quality backlinks and higher quality pages.
Google engineers are building an AI – but it’s all based on simple human desires to make something happen or indeed to prevent something. You can work with Google engineers or against them. Engineers need to make money for Google but unfortunately for them, they need to make the best search engine in the world for us humans as part of the deal. Build a site that takes advantage of this. What is a Google engineer trying to do with an algorithm? I always remember it was an idea first before it was an algorithm. What was that idea? Think “like” a Google search engineer when making a website and give Google what it wants. What is Google trying to give its users? Align with that. What does Google not want to give its users? Don’t look anything like that. THINK LIKE A GOOGLE ENGINEER & BUILD A SITE THEY WANT TO GIVE TOP RANKINGS.
Flash is a propriety plug-in created by Macromedia to infuse (albeit) fantastically rich media for your websites. The W3C advises you avoid the use of such proprietary technology to construct an entire site. Instead, build your site with CSS and HTML ensuring everyone, including search engine robots, can sample your website content. Then, if required, you can embed media files such as Flash in the HTML of your website.
If you own, manage, monetize, or promote online content via Google Search, this guide is meant for you. You might be the owner of a growing and thriving business, the webmaster of a dozen sites, the SEO specialist in a Web agency or a DIY SEO ninja passionate about the mechanics of Search : this guide is meant for you. If you're interested in having a complete overview of the basics of SEO according to our best practices, you are indeed in the right place. This guide won't provide any secrets that'll automatically rank your site first in Google (sorry!), but following the best practices outlined below will hopefully make it easier for search engines to crawl, index and understand your content.