This meta tag is used by all responsive web pages, that is those that are designed to layout well across device types - phone, tablet, and desktop. The attributes do what they say. However, as MDN's Using the viewport meta tag to control layout on mobile browsers indicates,
On high dpi screens, pages with
initial-scale=1
will effectively be zoomed by browsers.
I've found that the following ensures that the page displays with zero zoom by default.
<meta name="viewport" content="width=device-width, initial-scale=0.86, maximum-scale=3.0, minimum-scale=0.86">