How do Search Engines Work?
Before you can understand how to improve your search engine visibility, you must know the basics of how a search engine works. And just so we're on the same page, let's start with a definition.
What's a Search Engine?
A search engine is an Internet-based tool that identifies websites based on search terms you have entered. These search terms are referred to as keywords and key phrases.
Google is the most well-known search engine. Yahoo is both a search engine and a directory. Don't worry, we'll cover directories next.
Search engines create databases (or "indexes") through the use of robotic crawlers. These robotic web crawlers are often called "spiders." Both terms-crawler and spider-signify the way these robotic components scour the web automatically in search of websites to index.
When search engine crawlers find a particular website, they then crawl through the various pages of that site to determine what it's about. If the site has a good navigation system in place, crawlers can follow the hyperlinks from page to page, much the same way as a person would.
In this way, the search engine can identify what the website is about (or what it thinks the website is about) and thus how to categorize it.
In Plain English: Search engines crawl the web automatically and constantly. When they find websites that match a certain phrase (like "Austin SEO services"), they add it to their database. When you search through Google, you are actually searching Google's database, not the "live" Internet.
How Search Engines Work:
Although they determine their results differently, all search engines operate the same:
1. The searcher enters a key phrase into a search engine.
2. The search engine searches its database (or "index") to find matches.
3. The search engine displays the results in a ranked order based on relevancy.
All search engines perform steps one and two in basically the same fashion. Step three is where they differ. Each search engine uses a different formula (or "algorithm") to determine which results get the highest ranking, the second-highest ranking, the third-highest and so on.
These algorithmic factors represent things you can do to improve your search engine ranking (the brass ring of SEO).
Related item: What's a directory?