Search is an absolutely immune industry. Many companies rely on fortuitive rankings in the Search Engine Results Pages (SERPs) for their business to succeed. With the price of advertising, it's often far more cost-effective to invest in optimizing your site to move up these rankings, and see a greater number of customers find it via the search terms which matter to them.
With the boom of Search Engine Optimization (SEO) as an industry, and unbridled increases in consumer search queries, it's worth understanding the search process. Google recently released an infographic educating consumers on their practices, so read on for a break of just how search works.
Crawling & Indexing
This is the first step for any search provider. They send out small pieces of software, or 'robots', out to visit websites, read their content and travel along the links to and from landing pages. They'll note what kind of words a page uses, where it links to and what kind of websites are linking back to it. All of this information is collated, and used in the indexing process. Google sorts pages into categories, based on the notes they gathered. A website selling dog care products will be recorded as relevant to shops, dogs, animal care, collars, etc.
Algorithms and Retrieval
This is the actual part of the process where you see search results. The Google algorithms determine how relevant various pages are to different search terms. For instance an algorithm may mark links from respected news sites as high importance, so a website which has been linked to from them will move further up in the rankings. Conversely, the algorithms now react negatively to practices like 'keyword stuffing'. If that same dog care site features the word 'dog collars' listed in unnaturally high densities to appear relevant, the search algorithms will reduce its placement in search results.
The first two steps cover the initial process of finding websites and retrieving them for search results. Spam control is closer to an after show. Sites considered to 'spammy' are removed from search results entirely. These could be parked domains containing only advertising, or congregator sites with no original content. Some webmasters are able to dispute the sentence against them once it's been made, though so far the removal system has proven fairly successful at isolating spam sites.
The search process is not hard to grasp, and having a little understanding can indeed help for the future when managing a business or investing in SEO.