Meta tags have changed since SEO became a common practice, but two remain critical : The page title and the meta description. Stick to these when answering your interview question. The page title (Sometimes called SEO title) plays an important role in ranking but it is also important because it is the title that shows on the Search Results Page (SERP). It must use a keyword to rank well with Google but it must also be compelling so a user will want to click on it. The meta description does not affect ranking, but it also plays a role in the SERP because it also must make the user want to click on the search result. You should also mention that Google recently increased the character length limit of meta descriptions to around 280 to 320 (no one is sure of the actual limit yet).
