A meta description is a short blurb written by content developers that describes the content of the page in 1-2 lines, which appears under the headline in the search results of a search engine. It is recommended that you keep it short and to the point, and make sure to use your keywords to ensure that it shows up in the targeted search engine result page.
Although it is debatable whether the meta description directly affects your search engine rankings, it definitely affects whether or not a legitimate user clicks on the search result corresponding to your website, and this in turn will certainly improve your website rankings. Besides, prominent social media sites like Twitter and Facebook regularly integrate meta descriptions when links are shared onto their website as well, improving the shareability of your content and increasing the likelihood of users clicking on the links through these platforms as well.