Meta tags are keywords that are set within the HTML code of a website, which help explain what the site is about. They were of great importance ~10 years ago, but over time got to be abused by sketchy programmers and are no longer of any particular importance.
While some argue that you should put in meta tags even though search engines ignore them, it may be for the best to leave them out so that you don’t give competitors an easy way of seeing exactly which keywords you’re trying to rank for.