Meta tags help search engines analyse web pages. They use this data to help optimize search engine results. SEO (search engine opitmization) is a major area of today's marketing. The higher a web page ranks on Google (and the other popular search engines), the more oppertunity a business has to be seen.
In order to get the best results, you want the meta tags to accurately indicate the nature of your content. If your page is shown to the right people, and your content is good, your engagement will also be good. Search engines closely analyse how people interact with your page. If the wrong people are shown your content, your engagement will be low and less people will be shown the page.