Can you imagine using the internet without a search engine? These handy tools are now synonymous with internet use, helping users navigate through billions of pages and quickly find whatever it is they’re searching for. But how do they do it? What is a search engine, and given a simple, three-word request how does it return such relevant results in less than a second? A search engine is, fundamentally, a complex process with three different stages: crawling, indexing, and ranking. In this article we will take you through each of those stages, behind the scenes, explaining the role of the crawlers and why indexing is so important too, as well as how search engines rank pages to return the most relevant results.
Whether you’re running a business or own a website, it’s important to familiarise yourself with how search engines work and rank websites, so that you can keep bringing in targeted traffic. Search engine algorithms and practices are constantly evolving, so if you want to stay on top of your game, you need to be in-the-know on what techniques search engines use to rank your website in search results. In this guide, I’ll cover the core processes that determine where your website ranks and how you can optimise your content to achieve higher search rankings. So, let’s start with the first step: crawling.
Understanding Crawling: The First Step in Search Engine Operations
This is the first stage of crawling, where each piece of data serves as a starting point for crawlers to discover new, or updated content Formerly known as spiders, crawlers or bots, are automated programmes that roam the internet and bring data about web pages to the search engines. They do that by following links, one after another, much like a spider crunching its way through a network of invisible threads connecting dozens or even hundreds of different web pages. It all starts with a list – or, in engineer-speak, an inventory. Crawlers hire crawlers to crawl the web and build a list of all those crawlers, a so-called ‘crawler’s list’. A search engine’s crawler will traverse the whole of the internet from whichever end of this enormous list, and then keep on crawling, until there is no task left, until it has looked at (and indexed) every page that is deemed worthy of being looked at. The main purpose of crawling is to gather data about the content of the page, which can then be passed over to the next stage, called indexing.
Crawlers prioritise pages by offering more or less frequent visits to some websites. A website that’s dynamic, for example, reaching more people or maintaining high awareness would be crawled more regularly than a static one, lower in the charts. Of course, not every page on these valuable sites is crawled at the same rate. Search engines like Google have algorithms that maintain a persistent focus on what content crawlers should crawl first. Crawling is also ongoing since search engines don’t have time to rest knowing that more current information about the web is coming on a regular basis. Crawling is crucial to search engines’ ability to deliver fresh and relevant results to users – if they weren’t as adept at crawling efficiently and thoroughly, then staying in the race and satisfying people’s needs would be extremely difficult.
Indexing: Organizing Information for Quick Retrieval
And so the page’s content becomes ready for indexing, the job of labelling the page’s content for long-term storage in a database. When the crawlers’ work is done, the index period begins where crawlers’ information is stored. Search engines build what we may think of as the biggest libraries ever created – a repository of content that crawlers have examined. In this index, search engines analyse and classify the content they have retrieved. Each page is parsed for its text and images, as well as any other content that can be stored into the database. Then, report ranking search engines analyse this information without any human help, and decide where and how it will be stored in the index so that it can be retrieved for any query that might match a stored page.
Indexing is another key step for search-engine efficiency. Essentially, the process creates a searchable checklist of all the pages the search engine’s crawlers have found during their web journeys. This makes it possible for a search engine to spit out all relevant web pages in an instant after the user has entered a query. Without a list to check, a search engine would have to crawl the web in real-time with every single search query – an excruciatingly slow turnaround. Most indexing is complete without any human involvement, and the details of how search engines create their indexes are carefully guarded trade secrets. You have at least some control over how your pages get indexed, however. Providing appropriate SEO features such as meta tags, sitemaps and keyword-rich content tells crawlers what your pages are about and helps to make your content more discoverable and visible in search results.
Ranking: Determining the Order of Search Results
Once the web surfer has crawled and indexed, the number-one task remaining is to rank – to select from its index which web pages fall within the user’s search query, and in what order to rank them on the search engine results page (SERP). When a user typing in a keyword into a search engine, the engine’s ranking algorithm scans its index some nanoseconds later to determine web pages’ relevant visibility, authority and various other characteristics. While details of the ranking algorithms remain proprietary to the search engines – and the underlying logic is likely to differ from one search engine to another – we have a pretty good idea about the ranking factors that tend to affect a page’s position. These include the quality of the page’s content, the target keyword, user experience characteristics, and the quality of backlinks pointing to the page.
Another crucial ranking factor is intent based on measurement, or understanding of what a user is trying to find out. In years gone by, this might have been simpler; a search engine could just match keywords. But today, using machine learning and artificial intelligence, search engines can predict intent and then surface content in results accordingly. In newer search engines, these methods have evolved to further measure what users are seeking by rewarding content appearing on mobile-optimised sites, as well as rewarding content experienced at a faster rate (such as sites with quick load times) and those that have more time on site and lower bounce rates. These scoring mechanisms mean that sites seen to be performing better online (i.e., with high measuring indicators such as amazing SEO) are ultimately rewarded by being ranked higher in search engines. This is why ranking is such a highly competitive area of SEO, but also means that it’s constantly evolving.
The Evolution of Search Engines: From the Early Days to Modern Algorithms
The search engines that came right after altavista, Google, for example, only gradual deleted the myth of ‘faulty user’. As the history of search crawling and indexing attests, Google’s reinvented promise of a hopefully sensible and intelligible internet is only the postfactual, second act in the symbiotic coevolution of all-searching systems and users. The first, prepostfactual act of this coevolution was the ‘mythical’ dawn of keyword searches, where protopoststructural users attempted to crawl and index globalised webs of personal trauma and pheromones based on frontier logics of relevance powered by simple keyword matching. In this beguiling primordial history of web crawlers and rankies, the first search engines (eg, Yahoo and altavista) didn’t exactly misinterpret user intent (in the late-1980s, that wasn’t really a thing) or indexer control (equally not something prominently at stake in the uploading of the global web β version). Crawling web pages basically meant checking them out non-selectively, indexing meant noting their existence, and that was it. Websites were crawled, viewed and ranked. But since users back then didn’t really know what crawlers, indexers and rankings (or apps or big data or smartphones) were – they didn’t exactly know what they were searching for, either; it was all mythical. They just typed in a word or set of words.
(Today’s search engines, such as Google, use other more developed algorithms to rank pages, considering many other factors than just number of links, such as user engagement metrics, content freshness, semantic understanding of queries, as well as the authority and credibility of backlinks – again and again. Google evidently employs machine learning tools such as RankBrain to continue increasing the accuracy of its search results.) With the evolution of search engine technologies, website owners and businesses need to make sure that they do not lose their positions in the search engine results pages (SERPs).
How Search Engines Manage Crawlers and Their Impact on SEO
Crawler management is a key part of how a search engine works. Google, Bing, Yandex, whatever: each search engine keeps a list of available sites, called the ‘crawlers list’, onto which it dispatches its bots. Not every webpage is crawled equally. Search engines purposely follow pages that see frequent updates, host a lot of user activity, or are thought by Google to host authoritative content. Site owners can influence crawler activity, too, by blocking URLs from the crawler through robots.txt files, or by submitting sitemaps to urge crawlers to visit specific URLs more frequently.
A strong command of crawler behaviour is one of the hardest-headed SEO lessons to learn. If a crawler can neither access a site, nor one of its key pages, it will not be indexed. And it can’t be indexed if it’s not in the corpus that powers the engines’ search results. Checking regularly how crawlers behave on your site can help you identify technical problems that are thrown up during a crawl, that might be harming your SEO. Being crawlable is important for SEO, because if your site is user-friendly for a crawler, it is likely to be crawled more often and more thoroughly. This includes how quickly it loads, how many broken links it contains, but also aspects such as the filenaming structure across your site, and whether it has a clean and easy-to-navigate internal link architecture. The more SEO-friendly your website is to a crawler, the better your chances of ranking more highly in search engine results.
How to Influence Ranking: SEO Best Practices and Key Factors
Importantly, it involves a degree of technical optimisation, useful content that provides value to the reader or user and, not least, fit for purpose user experience. The ranking algorithms remain cloaked secrets as ever and change constantly – but we do have a sense of some of the key factors that can be leveraged to raise your profile. Good content remains critically important. Pages that are thoroughly researched, with quality, original content that engages and informs site visitors, continuing to rise to the top. Keyword-optimisation remains critical. But it must be done very naturally, and avoiding keyword stuffing is critical or risk the displeasure of the hidden eyes of the search engine spiders.
Furthermore, the performance of a website, such as speed of the page load, browsing safely on the HTTPS protocol and user friendliness on mobile devices also count. Another major factor is backlinks, ie links from other web sites to your website. It is still one of the most important factors in determining the authority and trust of your site. Search engines also look at user experience factors such as click-through rates and bounce rates (ie time users spend deflecting away from the page they’ve looked up). All of these ‘ingredients’ are considered to give users the most useful, organic and enjoyable experience on the web.
Conclusion:
Understanding how search engines work—particularly the processes of crawling, indexing, and ranking—is essential for anyone looking to enhance their online visibility. By appreciating the role of crawlers, the importance of indexing, and the intricacies of ranking algorithms, website owners can optimize their content and improve their search engine performance. While the field of search engine optimization is constantly evolving, the principles discussed in this article provide a solid foundation for improving your rankings. Staying informed about the latest developments in SEO and adapting your strategies accordingly will help ensure that your website remains competitive in an ever-changing digital landscape.
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