What is a search engine?
A search engine is an online tool that is designed to search for websites on the internet based on the user’s search query.
It looks for the results in its own database, sorts them and makes an ordered list of these results using unique search algorithms. This list is called a search engine results page (SERP).
Although there are various search engines in the world (e.g. Google, Bing, Yahoo, etc.), the general principles of searching and providing answers are the same across all of them.
The beginnings of search engines
- The first internet search engine was Archie Query Form introduced in 1990 – it was a simple tool that searched for FTP sites and provided them in the form of a list. It did not include any further content.
- Google’s predecessor – BackRub was introduced in 1996. This search engine brought the basic principle of backlinks and laid the foundation for the PageRank algorithm, which is used to this day.
- Google was launched in 1998 as a successor of BackRub and over the years became the most popular and dominant search engine in the world.
How search engines work
Search engines can differ from one to another in their ways of providing the answers to the user but all of them are built on the 3 fundamental principles:
The actual discovery of new webpages on the internet starts with the process called crawling.
Search engines use small programs called web crawlers (sometimes called bots or spiderbots) that follow links from already known pages to the new ones that need to be discovered.
Every time a web crawler finds a new webpage through a link, it scans and passes its content for further processing (called indexing) and continues in the discovery of new webpages.
Once the bots crawl the data, it’s time for indexing – the process of validating and storing the content from the webpages in the search engine’s database called “index”. It is basically a big library of all the websites.
Your website has to be indexed in order to be displayed in the search engine results page. Keep in mind that both crawling and indexing are continuous processes that take place over and over again to keep the database fresh.
Once the webpage is analyzed and saved in the index, it can be used as a search result for a potential search query.
The last step includes picking the best results and creating a list of pages that will appear on the result page.
Every search engine uses dozens of ranking signals and most of them are kept as a secret, unavailable to the public.
As Martin Splitt, Webmaster Trends Analyst, said:
“We have over 200 signals to do so. So we look at things like the title, the meta description, the actual content that you’ve got on your page, images, links, all sorts of things.” (Martin Splitt, Webmaster Trends Analyst)
What is a search engine algorithm?
The search engine algorithm is a term used to define a complex system of several algorithms that evaluates all the indexed pages and determines which of them should appear in the search results for a given query.
For example, the Google algorithm uses dozens of factors (many of them are well-known, while some of them are kept a secret) in several areas such as:
- Meaning of the query (understanding what the user means by using the exact words they used, what is the search intent, etc.)
- Page relevance (the search engine needs to find out whether the page answers the search query)
- Content quality (the algorithms determine whether the webpages are an excellent source of information based on internal and external factors; number and quality of backlinks are important factors here)
- Page usability (considers the quality of webpage from the technical standpoint – responsiveness, page speed, security, etc.)
Search engine optimization
Besides providing useful information for their users, search engines can also help brands to promote their websites.
Optimizing your website for the relevant search queries is an important part of any online marketing strategy since it can drive more traffic to your webpages.
The sum of all the practices and techniques the website owners do to improve their search rankings is called Search Engine Optimization (SEO).
What are the most popular search engines?
Although there are hundreds of search engines in the world, only a few of them dominate the overall search engine market and remain popular thanks to their quality, usefulness, etc.
In terms of worldwide popularity, Google has been #1 for years. This is the list of top 5 most popular search engines:
Google is the biggest and most popular search engine in the world.
Owned by its parent company Alphabet, Google dominates the search engine market with over 90 percent market share worldwide.
With all its features that include sophisticated algorithms, effective crawling, indexing, and ranking, Google provides excellent search results not only within its own search engine, it powers some other search engines as well (e.g. ask.com).
Bing is the second largest search engine. It was launched in 2009 and it’s owned by Microsoft.
Although it is impossible to compare Bing as a real opponent to Google with only 2 – 3 percent of the overall search engine market share, it is still a great alternative for those who would like to try something different.
Microsoft Bing is in many ways similar to Google, providing search result types like images, videos, places, maps or news.
Although Bing uses the fundamental principles of search engines (crawling, indexing, ranking) it also uses a special algorithm called Space Partition Tree And Graph which is based on the vectors for categorization of information and for answering the search queries.
Yahoo is a popular website, email provider and the third biggest search engine in the world with almost 2% of the overall search engine market share.
Once a very popular and dominant search engine, Yahoo was dropping in value over the years and became somewhat overshadowed by Google.
Nowadays, Yahoo competes with smaller search engines such as Bing or DuckDuckGo.
Yandex (from the term “Yet Another iNDEXer”) is a search engine that is popular mostly in the eastern countries.
Although it has less than 1 percent of the overall search engine market share, it is one of the most popular search engines in countries like Russia (with over 60 percent of all searches in the country), Turkey, Ukraine or Belarus.
Similar to Google, Yandex provides various types of services including Maps, Translator, Yandex Money or even Yandex Music.
Baidu is the most dominant search engine in China. Even though its overall worldwide market share is barely 1 percent, it represents over 80 percent of the market share in China with billions of searches every day.
Baidu is similar to Google in many ways. It provides classic blue links with green URLs and shows rich results the same way as Google does.