What is Keyword Stuffing?
Keyword stuffing is repeating the same keyword in a piece of content with the aim of improving its search rankings by manipulating search engines.
While we commonly use the term to refer to keywords stuffed into the visible content, it also extends to keywords stuffed into the HTML code, meta tags, alt tags, and anchor text of backlinks linking to the content.
Keyword stuffing worked back when search engines used keyword density to determine the relationship between a keyword and the content. However, search engines have updated their algorithms to detect it.
Whether it still works is open to speculation. However, it is a black hat SEO technique, and search engines have gotten better at detecting them. Google will demote rankings or deindex sites that engage in it.