The meta keywords tag is a legacy HTML element once used to declare a list of keywords a page was targeting, historically read by early search engines as a relevance signal before it was widely abused through keyword stuffing.
Google has explicitly confirmed it has ignored the meta keywords tag as a ranking signal since 2009, meaning including or optimizing it today provides no direct SEO benefit whatsoever.
Some websites and content management systems still include the field out of habit or legacy template design, but modern SEO effort should be focused entirely elsewhere.
We focus optimization effort on signals with genuine current impact within our On-Page SEO service.