Google like many other search engines use automated software that looks at the coding and text on websites. The visual appearance of the website does not matter to Google, flash animation is ignored and the only way to describe the process is like a blind person reading Braille.
Google will take the data from the coding and text and use this as part of the ranking for a website. The ranking effects the placement / positioning of the website for chosen keywords when searched in Google.
Google try to identify the most relevant and most important web pages to show these on page and the best being at the top.
Being on Google page one is important and ensuring your website ticks all the boxes in terms of ranking will ensure you are off to a good start.
Some Buzz words that you will have heard:-
Ranking: This is the actual position in the non paid area of the Google Search results for the keyword that is searched.
Page Rank: Google patented this system of PageRank (PR) and is / was an imortant factor that will influence search results.
Keywords: Keywords are those words and phrases that define what a web page is all about. When someone enters a search term or phrase in Google these special words are then checked in the database to see what websites contain these keywords.