# Search Engine Optimization (SEO) Cheat Sheet

SEO is a marketing discipline focused on growing visibility in organic (non-paid) search engine results.  SEO
encompasses both the technical and creative elements required to improve rankings, drive traffic, and increase
awareness in search engines.

# Search Engine Optimization (SEO) Cheat Sheet

SEO is a marketing discipline focused on growing visibility in organic (non-paid) search engine results.  SEO
encompasses both the technical and creative elements required to improve rankings, drive traffic, and increase
awareness in search engines.

## How Search Engines Operate

Search engines have two major functions: crawling and building an index, and providing search users with a ranked list
of the websites they've determined are the most relevant.

### Crawling and Indexing

Links allow the search engines' automated robots, called "crawlers" or "spiders," to reach the many billions of
interconnected documents on the web.

Once the engines find these pages, they decipher the code from them and store selected pieces in massive databases, to
be recalled later when needed for a search query.

### Providing Answers

When a person performs an online search, the search engine scours its billions of documents and does two things:
first, it returns only those results that are relevant or useful to the searcher's query; second, it ranks those
results according to the popularity of the websites serving the information.  It is both **relevance** and
**popularity** that the process of SEO is meant to influence.

**How do search engines determine relevance and popularity?**

Search engines typically assume that the more popular a site, page, or document, the more valuable the information it
contains must be.  This assumption has proven fairly successful in terms of user satisfaction with search results.

Popularity and relevance aren't determined manually.  Instead, the engines employ algorithms to sort the wheat from
the chaff (relevance), and then to rank the wheat in order of quality (popularity).

These algorithms often comprise hundreds of variables.  In the search marketing field, we refer to them as
"ranking factors."  Moz crafted a resource specifically on this subject:
[Search Engine Ranking Factors](https://moz.com/search-ranking-factors).

Add an How Search Engines Operate Section
Add an How Search Engines Operate Section