Is the written text within my web site important to search engines?

One of the the main rules in search engine ranking involves the location and frequency of keywords on a web page.

Imagine a search engine looking for a web site about "bananas"...
It makes sense that they first look at sites with 'banana' in the title. Pages with the search term appearing in the HTML title tag are often assumed to be more relevant than others to the topic.

Search engines will also check to see if the search keywords appear near the top of a web page, such as in the headline or in the first few paragraphs of text. They assume that any page relevant to the topic will mention those words right from the beginning.

Frequency is the other major factor in how search engines determine relevancy. A search engine will analyze how often keywords appear in relation to other words in a web page. Those with a higher frequency are often deemed more relevant than other web pages.

Naturally there is always a compromise between just using your keywords in your text and making it appealing to a human audience; and yes - that's the hard part.