The nuts and bolts of SEO marketing are keywords. They are important for one reason and one reason only. They allow businesses who seek search engine rankings to target their rankings by using the correct language.
If you think about it, this is what good marketing has always done. Marketers deploy language for the purpose of persuasion. They hope to get their target audience to think about things by using the correct language and getting them to think and take action. SEOs do this using a specific type of language that is intended for two audiences.
The first audience is the human audience. You want your online content to speak to your human target audience in a way that your human audience takes action. That action, you hope, is to do business with you.
Your second audience is the search engines. Or their spiders. Search engine spiders are computer programs that crawl the Web through links and analyze the content on the pages. Today's search engine spiders are very sophisticated compared to the spiders of fifteen or twenty years ago. They analyze keywords, links, images, and a host of other on-page and off-page factors to determine the rankings of web pages for specific key phrases.
Because search engines have a ranking system, search engine optimizers try to target their content to the spiders in order to influence them on that ranking system. The goal is to increase their chances at getting good rankings.
Keywords are the nuts and bolts, the basic building fundamentals, of good SEO. If you want to rank well, start with good keyword research.