The first thing that search engines do in order to find pages on the internet is to write “spiders,” which are automated programs also known as “bots” that “crawl” the web by starting with a “seed” set of websites. They’ll crawl out from there looking for all the pages that those websites link to. They then use those links to find the structure of the internet and to discover all the pages on the web, because the web is highly interconnected.
After they crawl the web, they need to build an index of these documents by doing what is called a keyword inverted index, which means that they store all the documents by the terms and phrases that appear on them or that they think are relevant to them.
Once they have got the indices, they calculate what is known as a query independent matrix, which is basically how they rank the webpages based on other attributes other than just relevance to the search query. For example, inbound quality links or social media signals.
In short, SEO is about trying to get as close as possible on the “food chain” to those “seed” websites. The basic process of SEO is actually quite simple in theory; it’s about getting your site on the indices and then being able to rank as well you possibly can. How do you do this? The following steps are the 4 commandments of SEO:
1. Content & Availability. The first step is to make your content accessible to the search engines. That means, your content must be in HTML text format; the search engine spiders cannot read images, forms, javascript, flash, or video. Search engines also need to have access to a crawlable link structure, one that lets their spiders browse the pathways of a website. Having good internal links and a sitemap are two important features to enable this on your site. 2. Keyword Research & Targeting. Your content has to target things that people are actually searching for on the web. Text that is not written in terms that users use to search will not be found by the search engines. For example, using the term “refrigerators” when people actually search for “fridges.” It’s therefore important to use tools such as the Google keyword tool. 3. Link popularity. When search results get competitive, links are the key factor that determines a webpage’s ranking on the search engines. Keep in mind that it’s not just about quantity but also about quality links. An example of a quality link is a link that says “dog training” and links to your dog training webpage, as opposed to a link that says “click here.” It’s also important that the site is a respected site, so beware the offers for links on the internet. Bottom line, you have to produce good content that people will want to link to, and market this content on the web. 4. Social Media. You need to ask yourself, how can I make my content relevant and valuable to people on the social network sites like Twitter and Facebook? This is because the social media signals such as Facebook “likes” or Diggs do make their way to the search engines, which take them into consideration as well.
Those are the basics of SEO.