SEO is the process of receiving visitors from from search engines for free also known as organic. All of ther major search engines including Google Yahoo and Bing have organic results. The search engines decide which website should be on page one for the keywords submited by the user.
This is the content of the page there are lots of things you can do to help your website do better in search engines, page title is important and header tags visit the website for monitoring and SEO Services for more information.
If You have a website that sells aquatic products then you will want your products at the top of page one for keywords that are relevant to that product, if you are selling fish food you would like to be on page one for the search term fish food, but you need to have the correct landing page, What if you are on page one for fish food and the landing page is goldfish food, the customer could be looking for tropical fish food, A visitor will make up their mind in 3 seconds weather to stay or go if they can't see what they are after they will leave, we would suggest that you target the category fish food for the search term fish food rather than a individual product.