The Web is the greatest collection of information the world has ever seen. It contains billions of pages of information about every topic known to man; so much information you could never exhaust the content that’s on the Web right now, to say nothing of the thousands of new websites launched every day. Search engines are the gateway used to access all of this information, and without good search engines the amazing wealth of information that is only a few keystrokes away would remain largely inaccessible.
An Indexing and Retrieval System
Search engines work by doing three things:
- Scouring the web for content.
- Indexing the content they find.
- Returning the results that are most relevant to a search term by comparing the term to the indexed content.
Web crawlers sometimes called spiders, locate a web page, and send its contents back to the search engine index. The web crawler then follows every link on the web page to capture all of the content presented on the website, as well as the websites that the page is linked to. In this way, web crawlers not only capture the content of a web page, but they also capture the links that tie different websites together.
Google, founded in 1997, dominates the search engine market with more than 60% of global market share.
The information sent back by a web crawler is analyzed by the search engine and indexed. The search engine indexes web pages based on the web page’s title, headings, paragraph content, subheadings, and any other information contained on the page. The search engine uses this information to determine which topics the page provides relevant information about.
When a user visits a search engine, and enters a search term, or query, the keywords are compared against the contents of the search engine index. The relevant pages, sorted by relevance as determined by the search engine, are then returned back to the user.
The way that each search engine decides which results to return is called the search engine algorithm. Each search engine’s algorithm is proprietary, and varies to some degree, meaning that each search engine will return somewhat different results for the same search terms.
Getting the Most out of a Search Engine
Have you ever searched for something on the Web and been unable to find exactly what you were looking for? If you don’t know them already, there are a few advanced searching tricks you can employ to get the most out of a search engine, and to track down hard-to-find information.
Google, Yahoo!, Bing, and Baidu command more than 97% of all global search engine market share.
Most search engines allow the use of boolean operators, which are words you can use to refine your search. The most common boolean operators are AND, OR, and NOT. Combining search terms with these operators will yield more specific results. If you’re looking for information from a specific webpage, a useful trick is to limit your search to just that domain by prefacing your search with site:domain-to-be-searched.com. Another helpful action is to limit your search to results that match a phrase perfectly by surrounding the phrase in parenthesis like this: “exact phrase you are searching for”.
There are many other tools and operators you can use to get the most out of a search engine, and if this is a topic you want to learn about, check out this article to get started.
Search Engines You Should Know
The three most popular search engines are Google, Yahoo!, and Bing. Google is by far the most used, and the combined volume of the top three engines makes up more than 80% of global search engine volume. If you add in the volume of the leading Chinese-language search engine, Baidu, you are left with less than 5% of total search engine volume to spread between all other search engines.
Google was founded in 1997, and today dominates the search engine market with more than 60% of global market share. In addition to keyword searches that return web pages, Google allows you to search for several other types of content such as:
- Images and videos
- Shopping pages
- News articles
- Scholarly articles
- Airline flights
Yahoo!, founded in 1995, and Bing, unveiled by Microsoft in 2009, both work very similarly to Google and offer comparable content searching capabilities. However, due to algorithm differences, search results produced by each search engine will vary from the results provided by the others.
Google is available in 123 different languages while Yahoo! is available in more than 30 languages, and Bing is available in 40 different languages. The availability of each in multiple languages has driven the adoption of all three search engines around the world. Baidu, on the other hand, is focused on the Chinese search engine market. This focus has resulted in Baidu being the market leader in China, commanding more than half of all of China’s internet search queries.
All of the leading search engines depend on advertising revenue, and track user behavior to deliver targeted ads. Most users are aware that this is happening and don’t care. However, enough users do want to maintain their anonymity that a few search engines have appeared that do not collect user data. The most noteworthy search engine in this category is DuckDuckGo.