<meta name=”viewport” content=”width=device-width, initial-scale=1″>

The idea is to set up a virtual viewport for the page (“layout viewport“) that fit the small screen of mobile or tablet (“visual viewport“) (normally equal to the width of the device, in this case, it is said this is “idea viewport“), which could let the full page completely renders in the mobile and tablet.

content also include: height, minimum-scale, maximum, user-scalable