What is a Search Engine?

Mary McMahon

A search engine is a set of programs used to search for information within a specific realm and collate that information in a database. People often use this term in reference to Internet search engines, which are specifically designed to search the Internet, but they can also be devised for offline content, such as a library catalog, the contents of a personal hard drive, or a catalog of museum collections. These programs help people to organize and display information in a way that makes it readily accessible.

Internet search engines help users search for information relevant to what they seek.

There are three aspects to a search engine: crawling, indexing, and searching. When one crawls, it looks for new content that was not present during the last crawl, including updates to files and web pages. Then, the programs index the information, pulling out specific keywords to categorize it. On the Internet, for example, indexing relies heavily on keywords in web pages and meta tags that provide information about the page.

A library catalog is an example of an offline search engine.
A library catalog is an example of an offline search engine.

Once the information has been indexed, information about how to access it is stored in a database. Some programs also store or “cache” information to make it easier to retrieve. When someone searches the database, it spits out results ranked by relevance. On wiseGEEK, for example, a search for “giraffe” will turn up articles related to giraffes, including, of course, "What is a Giraffe?"

While all search engines work in similar ways, their usefulness can be quite varied. They rely heavily on complex algorithms to rank the relevance of their search results, especially those for common keywords. Users tend to gravitate to ones that return results they like, with Internet sites like Google®, Yahoo!®, and Bing® warring for users with various features that are designed to make their searches more appealing and more relevant.

Google® has managed to become so associated with the process of conducting a web search that this process is often colloquially known as “googling.” The company is actually not very pleased with this, as it fears that lower case use of its name, along with generic use, could contribute to trademark dilution.

Many Internet search engines are smart enough to learn from their users, incorporating user activities into their relevancy rankings. They also rely on information like links from other pages and a site's reputation to rank search results, all within the fraction of a section. Adept users can sometimes manipulate search results, but many programs change and evolve to help combat this practice.

Search engines allow people to find relevant search results.
Search engines allow people to find relevant search results.

You might also Like

Discussion Comments


I found a Visual Search Engine which users can view three of the major search engines Yahoo, Bing and Google simultaneously, I use it all the time. It's called YoMeta.



You raise some very important questions. It is my personal opinion that books will retain their value... as antiques and relics of our current spoken language. One day the speech of the internet will become commonly spoken verbally as a conglomerate of terms from various languages. Search engines and various new software and hardware will empower the masses to the point where we are all very highly educated and interpersonal from the moment we awaken to the time we go to bed. The world is expanding (and shrinking) faster than it ever has.



If what you said is true about libraries, what is the risk of real books falling into disuse? I worry that all of our investments in books for college, school, etc. may become a waste of money at some point in the near future. Will books become accessible and free? What of publishing companies? If everyone learns how to learn anything on the internet, what will be the use of books, and how will we make money?


Not too far in the past, libraries were the key to learning just about anything, but today we have the internet. Increasing the accessibility of millions of documents on billions of subjects is an empowerment to the masses, and has enabled search engines to all but own the world of epistemology.


Search engines are being used to improve translation, and with the vast resources of the internet available, understanding language boundaries are enabling us to bridge them faster and faster. It is likely that search engines will soon be a key tool in immense technological breakthroughs.


I found a new niche search engine, its called

Gezmmo Search

Post your comments
Forgot password?