Since its launch in 1998, Google has become known for its glasses, mail server, and cars. At its core, however, the multibillion-dollar company is still defined by its original purpose: Acting as a search engine. In one single day, more than three billion searches are made through Google, and it boasts more than one billion regular monthly users. Despite this ubiquitousness, many still don’t understand how it works.

In short, a search engine provides answers for users’ queries. When someone types in a query into Google’s search bar, Google’s automated robots ‘crawl’ the vast expanse of webpages, images, PDFs, and other files on the internet in search for an answer to that query. Google’s crawlers—the ‘Googlebot’—travel the internet through hyperlinks that direct it from one page to another. Basically, millions of little robot crawlers travel from webpage to webpage in search of the correct match, using hyperlinks as bridges between pages.

As the crawlers search, they create a massive index of files that can be recalled faster for future searches. Stored in data centres across the world, this index is roughly 95 petabytes (95 million megabytes) in size. Despite this size, not all links or webpages are included. Certain pages can be deemed ‘nofollow’ or ‘noindex’ by a site’s webmaster. The latter tells a crawler to prevent the page from appearing on search engine result pages (SERPs) while the former tells search engines to ignore any links that take users from that page. 

A variety of factors are known to affect where a webpage appears on a SERP. For example, if a user is searching “McGill University” the webpages that will appear high on the SERP will need to have the words “McGill” and “University” appear together, multiple times on the page. Webpages will get also get a boost if “McGill University” is in the heading, title, or URL of the page. The most important factors, however, are whether other pages link to the webpage and the website that the webpage belongs to. For example, if a webpage received many hyperlinks to it from a reputable and frequently visited website such as the New York Times it will appear higher in SERPs.

 In its early days, SERPs could easily be manipulated by webmasters to direct more traffic to their sites. Common tactics included adding hidden text or links to webpages or stuffing a webpage with an unnatural amount of keywords. These features trick the search engine into delivering pages that do not actually meet the query, causing it to underperform and provide useless information to the user.

Google uses over 200 different factors to provide search results, including things like site speed, and whether or not a website has a secure domain. Although the intention of having this many ranking factors is to show the most accurate results, in some cases, this can mean that Google will show two different users who type the same query different results. This is because Google is able to create a personalized searching experience, based on a variety of factors such as the user’s physical location, browser language, and previous browsing history. For example, when users search “cellphone,” they are served localized results for cellphone dealers based on where the search originated from. 

The result is an extremely powerful and accurate machine to answer the world’s questions. Although a more personalized browsing experience can be useful, it comes with a cost: A loss of privacy. The only way that Google is able to provide such hyper-targeted search results is by collecting and analyzing a massive amount of personal data from its users. As users use Google to acquire information, they also surrender their own, often without realizing. Sex, age, location—and even interests—can be ascertained from browsing history,

Despite the ever-growing issues of online privacy, there is no denying that the electronic exchange of data is a powerful tool that has shaped modern society. Today, a person can acquire a degree online, read a book off of a webpage, and send important documents to their loved ones with ease. This electronic revolution has streamlined society, and facilitated the lives of millions. And there’s no denying that throughout this process, the major player has been Google.