About Search Engines
What is search engine?
Simply put, a search engine is a computer program that does keyword searches against a database.
How does that apply to the Internet?
The Internet consists of hundreds of millions of web pages. Because they're scattered all over the world, on millions of computers, it becomes quite difficult locate information. It's truly like a "needle in a haystack". Finding a needle in a haystack would be quite difficult. But suppose you had a tool to help you, say a magnet or metal detector. Wouldn't finding the needle be much easier?
Ok, now imagine a millions of haystacks, each with multiple needles. How do you keep track of which needle is in which haystack? That's where a database comes in. The location of each needle in each haystack is recorded in the database. Once that is accomplished, locating a particular needle simply means doing a search of the database.
How do the search engines get the web pages in their databases?
Search engines have different ways of accomplishing that. This is where it gets complicated -- and controversial. First, most search engines allow user submissions. That is, users can alert the search engines to the existence of their web sites. Other search engines use programs (robots or spiders) that automatically go out to other web sites and catalog them, tirelessly moving around the web. Many search engines use both techniques. Some search engines simply just use other search engines. They are called meta search engines. Search engines that rely exclusively on user submissions are actually directories.
That doesn't sound too complicated or controversial.
No, where it gets complicated and controversial is deciding which result is listed first. Most people will not go through too many links to find something. They want to see it in the first 5-10 results. Businesses are the same way. They want their URL to be the number one URL. So how do search engines decide who's "number one"? That's where the complications and controversy arise. The search engines use sophisticated, complicated algorithms to rank the results.
Those algorithms take into account hundreds of factors, analyze them, the display the results in some kind of ranking order.
What kind of factors do the search engines analyze?
They analyze the title of the web page, the words in the page and how many times each word occurs. They analyze links and the HTML of the web page. They analyze the URL of the web page. And so on.
How do I use a search engine?
First of all, the number of search engines available is in the hundreds, at least. They all use different algorithms and have different databases. Therefore, as far as search engines go, "your mileage may vary."
There are two keys to using search engines. First, be as specific as possible when thinking of keywords to search for. And second, don't believe everything you read.
For instance, if you type the word, "Homer" into a search engine, you could get anything from Homer Simpson, Homer, the author of The Iliad and The Odyssey or Homer, Alaska. You have to be specific. Also, you can run into false, misleading, uninformed or biased information. Analyze what you find carefully.
Anything else?
Yes. Since search engines are so popular, many have redesigned themselves to be "portals" or a starting point to everything on the web. They offer personalization and customization, free e-mail, chatting, games, shopping, the latest news and sports scores and so on. But even with all those extra services, they are good search engines. Here's a list of search engines to help you get started.