How Do Search Engines Work?

You know that search engines play an important role in helping people find your website, but how does it all work? How do search engines provide results? What determines your ranking? Let’s break it down.

Google does a lot behind the scenes to provide you with search results. First, Google uses software called “web crawlers” to crawl the web, following links page by page until every page (over 60 trillion and counting) has been discovered. You may recognize Googlebot, the most well-known crawler. The crawlers provide Google’s servers with data about those webpages.

Google then indexes all of that information based on the content of the pages. You can think of the web as a book, and Google as the index in the back of the book that helps you to find the pages relevant to the information you want. Google has programs that determine which sites to crawl, and how often. Crawlers pay attention to new sites and pages, as well as changes to existing pages.

Though most website owners don’t need to set up any restrictions for how Google crawls and indexes their website, you do have the option to choose how Google crawls your site using Webmaster Tools and a file called “robots.txt.” With this file, site owners can choose not to have their website crawled by Google, or they can give instructions on how to process the pages on their site. For example, you may wish to have duplicate content or patient education excluded from the crawl, because your rankings could potentially be affected by content that is used multiple times on your site or on other sites.

From the Index to Search Results (In Less Than a Second!)

Let’s say Mr. Brown is searching for information about a partial knee replacement. He types in “partial knee replacement” on Google and immediately gets results. But how do all of those results pop up so quickly? The answer is the algorithm.

The algorithm is a set of programs and formulas that look for signals in the index to find content relevant to your search query. Currently, there are more than 200 of these signals, or clues, that the algorithm looks for to determine what results to show. So, every time you search for something on Google, the algorithm looks for these 200 clues to provide you with results. Amazingly enough, the algorithm can do all of that within 1/8 of a second!

The main purpose of the algorithm is to provide the most useful results. This is why good quality content is important. Because of the way the algorithm is set up, you can’t expect to rank by simply filling up a webpage with keywords without providing content that is actually useful. The algorithm recognizes tactics like keyword stuffing, and those pages will not receive a high ranking.

The algorithm is constantly being updated to ensure that you get the most relevant results every time. Let’s go back to the search for partial knee replacements.

Mr. Brown is interested in information about total knee replacements, and would also like to know if any local doctors perform this procedure. The algorithm will look through the index for these clues related to this search query and provide the most relevant information, based partly on how often the information has been cited or linked to from other websites. The algorithm is even set up to look for geographic clues, so Mr. Brown will find information about partial knee replacements from nearby medical practices whenever possible.

What if he misspelled the search query? No problem! Google’s algorithm is set up to identify misspellings and correct them.

Squashing Spam

In addition to indexing the web and creating algorithms to provide you with relevant search results, Google also works to fight spam. Spam sites will attempt to get to the top of search results by using tactics such as repeating keywords in the content or creating loads of low-quality links to the site from directories or forums. As a result, legitimate websites get buried and become harder to find.

Google’s algorithms can detect most forms of spam, and automatically remove those sites from search results. Google also has a team that manually reviews sites for spam not caught by the algorithm. In those cases, Google will notify the website owners so that they can take steps to remove spam from their websites.

The Reason for Great Content

For something that seems like such a quick and simple process on our end, there is a lot going on behind the scenes to provide you with search results. Google’s crawlers crawl the web and index the content. When you search for something, the algorithm searches for clues in the indexed content to provide you with the information you’re looking for. The algorithm changes frequently, but understanding how it works can help you stay on top of things.

The bottom line is this: Google is set up to provide people with useful search results. Focus less on ranking tactics and more on providing useful, relevant content, and you should be just fine.