In many ways, I've learned more while explaining a concept than I do reading or listening about it.  That's why it is always intriguing to explain Search Engine Optimization (SEO) to someone who doesn't work in the realm of web development. 

Over the weekend, I was explaining SEO to a librarian I know. During this conversation I was trying to explain the field to her in terms that I assume she would understand.

For example, I explained that a search engine is like a librarian whom people approach to find the most relevant information about a topic.  In the case of search engines, people ask by using a keyword.  Then the search engine provides a list of sites in order of relevance.

To do this, I explained, that search engines gauge many factors of each information source that a librarian must also consider.  These factors include: the age of the source, who cites (links to it on the Internet) it, how often it is updated, etc. 

During this discussion she mentioned something that intrigued me.  Librarians, like us all, need to conscientiously work to avoid providing biased information.  For instance, a patron may ask a librarian for a book about the librarian's religion, and the librarian may feel compelled to refer the patron a book written by someone who sheds a positive light upon the religion.  Whether this is truly the best book or not, the librarian must refrain from unduly emphasizing one factor of relevance over others.

Likewise, search engines must also work to avoid providing biased information.  This was the case years ago when they weren't as selective with the link factor when assessing a site's relevance.  Many web developers would create virtually useless sites to a human that were chock full of links (aka "link farms") to sites that they were trying to get ranked well.  The search engines eventually became more discriminating when assessing links to prevent such manipulation so that they could provide less biased results to those who used them to search for information.

Although I've understood the concept of link farms before my discussion with my friend, her comments helped me understand SEO in a better way.  Thus, I would suggest to anyone to explain the complexities of their field to someone else.  It helps.