What words to use and why from an SEO perspective

First things first, content is king, and the most vital part of any SEO (Search Engine Optimisation) strategy.

Linking your content to your target markets vocabulary is step 2. Defining your target market is the real trick that needs to be mastered, as you don't want people coming to your site then leaving in a hurry because they are not interested in your subject matter, and feel that they have been deceived by your marketing tricks.

Understanding your target market and their vocabulary is vital as you need to understand what words they would use to search for your information and optimize your page with these words in mind. Mis-spellings, foreign language words, and local slang are important, and all major search engines are beginning to use these concepts to establish the intent of a searcher from the words he / she has used in the search box.

all past searches are stored and evaluated by search engines on an ongoing basis to determine trends and search patterns within their user base. These results are factored into the SEA (Search Engine Algorithm) to determine a users intent, and search engines are beginning to get quite good at this.

This implies that your content must be well written and match up to your META TAG info, especially the keywords meta tags and any categories you may have listed in the head section of your page. Connecting the intent of an end user to your page is not a simple task, and a host of  variables will be factored into this section of the Search Engine Algorithm, with MANY OF THESE FACTORS BEING WAY OUT OF YOUR CONTROL.

Things like past searches done by others and current trending topics will be at the top of this list used to determine the end users intent at the search engine. Read this post for a deeper understanding of how search engines are using user intent factors.
http://searchengineland.com/is-googles-synonym-matching-increasing-how-searchers-and-brands-can-be-both-helped-and-hurt-131504

Bottom line is GOOD CONTENT using your intended target markets vocabulary and words that you believe your intended target market will use in search boxes when looking for your information, in well worded copy.........