How do search engines work?

How do search engines work?

There are two basic types of search engines. Crawlers/Spiders and Human Controlled.

Crawler Based Search Engines
Crawler or Spider type search engines crawl through the Internet finding places to go like spiders through the World Wide Web. They will eventually read everything they can find. They provide search results based on what they have crawled.

Human Controlled Directories
Human Controlled Directories are exactly what the name implies. A human reviews what you submit to their directory. This submission is normally only the main URL and a very brief description of your site. This is very good if you can get listed, however it can take a long to time to be added to their directory. If however you have a fantastic site, the directory may find it on their own, create a description, and add your URL to their directory.

Hybrid Search Engines
This type of search engine uses sources of data from both Crawler Based and Human Controlled search engines. Hybrid type search engines will often prefer Human Based submissions. However there is only so much time in the day and so many people reviewing the millions and millions of websites. You may still appear on search results if you have not yet been listed by human powered directories.

How does a crawler type search engine work?
A crawler type search engine provides results to searchers by using three components. These search engines crawl or spider through a website and follow the links within the site and read the pages. As the spider finds changes or new pages, it adds this information to the engine’s index. The index is a database of everything the search engine has found crawling through the Internet. If a page has not been added to the index it can be found through search. It is possible to have been spidered, (crawled), but not indexed. This may take some time. The last portion is the sorting of all this information from your site against all the other millions of sites that have been indexed. The search engine’s software reads all these pages and sorts and ranks the information by what it believes is the most relevant.

Search Engine Optimization Guides
Search Engine Optimization Basics
Search Engine Optimized or Friendly URLs.
Search Engine Optimized Title Tags
Search Engine Optimized Content
Search Engine Friendly Header Tags
How to get other sites talking about your pages.

More Search Engine Optimization Topics
How do search engines work?
Submitting to search engines
Submitting to directories
Creating effective keywords