Google basics explained - on video

This short video gives a very brief explanation of the basics of Google's methods to index sites and what variables are most important for ranking high in the SERP's (Search Engine Results Pages' / positions).

three things that are most important for search engine are
1) how to craw the web most efficiently
2) index the pages, and sort according to some criteria
3) Rank all pages then serve the pages to searchers according to their needs

To ensure that your pages are indexed in search engines you need to ensure that  search engines find your pages through links from other sites, and that your pages have internal links so that all your pages can be found by any search engine that locates any one of your pages.

Once your pages are indexed by search engines they perform quite a few mathematical tricks useing a host of variables such as but not limited to the list below to give some kind of score to your page. Then the search engine will store this value along with a number of pre calculated variables that will be used to evaluate an end users search query and return a SERP (Search Engine Results Page) in their indexing system.
1) the specific words within your pages, and how they are used, where they are in relation to each other and other data on your page.
2) all inbound links form other websites including the anchor, text where the link is on the page, words near to the link, and words on the landing page which the link refers to.
3) all out bound links, including anchor text, words near the link, words on the landing page of the link, and the context of the link related to other onpage data.
4) all internal links linking to the specific page as well as all internal links linking to other pages within your site taking the page content and many related issues into account.

When an end user submits a search query this is search query is compared with the indexed words and some very  advanced mathematical algorithm is used to determine the end users intent and match this intent with the aboutness of your pages. Once the search engine has determined the best possible matches from its index with a searchers intent the search engine delivers a SERP (Search Engine Results page)