Before 2011, keyword inclusion in your content and meta tags was a nearly surefire way to ensure that a page of your site ranked for that specific keyword. This is where the concept of “keyword density” came in, with some sources recommending a density of two or three percent on any given page (meaning two or three percent of words or phrases within the body of your content were your exact target keywords). Then, the Panda update came and everyone started questioning whether density was still a thing; was it better to include that specific number of keywords, or focus on creating great, user-focused content?
https://www.forbes.com/sites/jaysondemers/2017/09/13/is-keyword-density-still-important-in-seo/#79b05bb778dd/