Keywords are words that are shorter in length but they carry ideas of the topic that your content is about. If you go by SEO terms then keywords are the words that searchers all over the world enter into search engines to get instant organic results. When you assemble everything on your web page and try to portray the whole through long tail keywords, short tail keywords or mid tail keywords, those become your primary keywords. These are the methods to generate organic leads.

If you're the website owner or you're the one involved with content writing you know what it means to have relevant keywords on your page. The more relevant your keywords are the better will be your chance of appearing on top of the search results.

Keywords are necessary because they are the medium through which what people are searching for and the content you are providing to fill that are connected. By being ranked on search engines your goal is to drive organic traffic  to your site from the search engine result pages (SERPs). The keywords that you choose to include in your page will play an important factor in deciding what kind of traffic would you get. The focus should lay on what the visitors must be searching for. You must use keywords by focusing more on the language that the visitors use, and the kind of content they seek.

Keywords are important to SEO for so many different reasons and all for marketing purpose.

It helps you identify your clients and speak the language of the target audience.

Helps you improve your content in order to attract your target audience.

Improve search engine rankings.

Present right content in front of right set of audience.

Communicate to Google what your web page is about.

All of these matter for SEO. Keywords help your customers make their way to you while you provide them with the exact services they are looking for.