Keywords are ideas and topics that define what your content is about. In terms of SEO, they're the words and phrases that searchers enter into search engines, also called "search queries."
Keywords are as much about your audience as they are about your content because you might describe what you offer in a slightly different way than some people ask for it. To create content that ranks well organically and drives visitors to your site, you need to understand the needs of those visitors — the language they use and the type of content they seek. You can do this by talking to your customers, frequenting forums and community groups, and doing your own keyword research with different keyword tools available in the world of SEO i.e Search Engine Optimization