If you want your web content to rank highly in search results for a certain keyword, it is important to use that keyword prominently in titles and text on your web page(s). Avoid uncommon terms if there are more commonly-used terms available. For example, don’t write about “food cooling units” when your audience is more likely to be searching for “refrigerators.”
Most importantly, don’t abuse or overuse keywords. Use them naturally and strategically. Remember, design for visitors, not search engines.
Read more about Search Engine Optimization in Mozilla's Beginner's Guide to SEO at moz.com/beginners-guide-to-seo/.