What you want here is a primary keyword and hopefully a set of related secondary keywords that share the searcher's intent. So the intent behind of all of these terms and phrases should be the same so that the same content can serve it. When you do that, we now have a primary and a secondary set of keywords that we can target in our optimization efforts.
Thanks for the helpful information discussing the differences and similarities between SEO and SEM. The information was enlightening because a search engine optimization company like the one that I own is relatively new at starting. We believe everyone should always check out their sources because every different perspective is very different so all approaches can be understood differently.