Search engines today help people find the information they need from among the millions and millions of web pages that the World Wide Web now contains. Without such search engines, looking for the type of information one requires from a vast repository such as the Information Superhighway may prove to be a very tough challenge. Without search engines, people would need to memorize each URL or web address that they use everyday. This would limit the type of websites that users may be able to go over. Not only that, users may not be able to explore efficiently the vast resource of information that the Internet contains if it were not for search engines, especially those unknown to the user.

And just like a library needs a librarian to help visitors find books and categorize each one for easy retrieval, a vast information source such as the Internet would also need such a guide. And that guide happens to be the humble search engine. But there is nothing lowly about search engines. People would get lost in the maze of information online if it were not for search engines to help provide the guidance. Different search engines today come in different types and use different methods.

One type of search engine is the directory based search engines. This type of search engine depends on a compilation of website listings from where the engines try to retrieve information. Directories are usually compiled with the aid of human editors who check out each site with their accompanying descriptions and review them for relevance as well as place them in a chosen category. This allows directory based search engines with a website listing that may be able to provide a higher level of relevance to every search query made. The only disadvantage of this type of search engine is that it may only be able to go through a miniscule part of the vast Internet information repository since it requires human intervention in trying to compile and review different sites that become a part of the whole directory. Their efficiency would depend on how fast the human component may be able to provide the work required, which can be pretty slow if compared to the growth of new websites that may come out everyday.

Another type of search engine is what is known as crawler-based. This type of search engine usually creates its website listing automatically. It makes use of a crawler program, also called a spider, that crawls throughout the web and take a look at the different websites out there. The web crawlers then take the relevant information contained in these websites for proper indexing. This method tries to take out the slow human component of compiling a search listing, allowing search engines to somehow keep at pace with the vast number of new websites that come out daily. This type of search engine allows the user to more or less check up on the information contained in the Internet on a wider scope and range than do directory-based search engines. It only disadvantage is that it may sometimes be able to provide results with a lower level of relevance since they can easily be manipulated, such as providing results with more advertisements than actual data.