Search Engines
Information on search engines such as: Google, Yahoo, MSN and Ask
Search Engines try to help internet users find the most relevant information or resources online.
About Search Engines
Search engines "crawl" websites by using computer programs to visit a website and download all the data they need and store it to a database. Search engines then use this stored data, along with an algorithm (more computer programming) to return the most relevant results to people who use their search engine to search the internet.
Search Engines by Market Share*
* As of March 2008, Source: SearchEngineLand.com
What search engines look for when crawling a site
When search engines crawl a website they are checking for a few main things: links, text and images/videos.
Links are the most important and (most agree) play the most significant role when search engines determine how to rank websites in their results. Search engines follow crawlable links on each website to other websites and store information on how each website is linked to another.
Text (or content) is the backbone of websites. Search engines read plain HTML text to understand what the page or website is about. Search engines love good content, and especially love lots of new good content (websites who post quality pages on a regular basis).
Some try to spam search engines by creating several pages of the same content on their website to look more authoritative, but search engines have picked up on this practice and now can penalize site that have duplicate content.
Images and videos are currently the least important of the 3 items in this list, but search engines still use images and videos to understand what a page is about.
Search engines are developing new technologies to read and understand images and videos on websites, so images and videos will play an increasing role in the future.
In theory, more links pointing to a website the more popular it is unfortunately, some have spammed search engines by creating sites for the sole purpose of increasing the value of the website it links to. Search engines caught on to this practice, and now can penalize these types of sites.