A meta description is the short paragraph of text shown under your page’s title in a Google result, summarizing what the page is about. It is a small caption, but it does real work.
Google does not use it as a ranking factor, but it is your ad copy on the results page. A clear, specific line that answers what the searcher wants can be the difference between your result earning the click and the one below it earning it instead. Write it like a sentence you would say to a customer: name the service and the place, and make a plain promise the page actually keeps. Leave it blank and Google writes its own from whatever text it finds, which is often a poor pitch for your business.
I write a purposeful title tag and description for every page, so the search result reads like a human wrote it and not like a machine scraped it. It is a small thing that decides a real one, because a page still has to earn the click before it can do anything else for you.