1) Most people click on the first 10 results shown on the first page after a search. If you spend a little bit of time and have a little more patients to click beyond the first 5 page, you might find yourself a bargain. Search engine does not always return the best site but return sites that the search engine think most relevant.
2) SEO or Search engine optimization is an area of studies to make a website seems best suite to a phrase of your search result. There are White hat SEO, the good guy that abide by the rules, the Gray hat SEO, guy that is on the fence, sometime good and sometime bad and finally the Black hat SEO, guy that would do anything to deceive the search engine in order to rank on high in search result.
3) Search engine is a type of utility website. The other day, I was talking to a friend who ask me what is a website and what is a blog? I would say there are many types of website.
Blog is a type of website where you can post contents and it has the ability to help you manage your post.
Google, Yahoo or Bing belongs to a special type of utility website that is commonly known as Search Engine. They help people find other websites using phrases or keywords. Besides the big three there're probably hundreds other smaller search engine e.g Dogpile.com, Altavista.com, Metacrawler.com, Lycos.com and excite.com
And recently, Social Networking are the hottest type of website. Facebook has 500 million users account and if it is a nation, it would have been the thirth most populous nation in the world after China and India.