Search Engine Robots (Part I)

How They Work, What They Do

Automated search engine robots, sometimes called "spiders" or "crawlers", are the seekers of web pages. How do they work? What is it they really do? Why are they important?

You'd think with all the fuss about indexing web pages to add to search engine databases, that robots would be great and powerful beings. Wrong. Search engine robots have only basic functionality like that of early browsers in terms of what they can understand in a web page. Like early browsers, robots just can't do certain things. Robots don't understand frames, Flash movies, images or JavaScript. They can't enter password protected areas and they can't click all those buttons you have on your website. They can be stopped cold while indexing a dynamically generated URL and slowed to a stop with JavaScript navigation.

How Do Search Engine Robots Work?

Think of search engine robots as automated data retrieval programs, traveling the web to find information and links.

When you submit a web page to a search engine at the "Submit a URL" page, the new URL is added to the robot's queue of websites to visit on its next foray out onto the web. Even if you don't directly submit a page, many robots will find your site because of links from other sites that point back to yours. This is one of the reasons why it is important to build your link popularity and to get links from other topical sites back to yours.

When arriving at your website, the automated robots first check to see if you have a robots.txt file. This file is used to tell robots which areas of your site are off-limits to them. Typically these may be directories containing only binaries or other files the robot doesn't need to concern itself with.

Robots collect links from each page they visit, and later follow those links through to other pages. In this way, they essentially follow the links from one page to another. The entire World Wide Web is made up of links, the original idea being that you could follow links from one place to another. This is how robots get around.

The "smarts" about indexing pages online comes from the search engine engineers, who devise the methods used to evaluate the information the search engine robots retrieve. When introduced into the search engine database, the information is available for searchers querying the search engine. When a search engine user enters their query into the search engine, there are a number of quick calculations done to make sure that the search engine presents just the right set of results to give their visitor the most relevant response to their query.