Area on the computer or device screen where you are viewing a web page
Viewport width is not always the same thing as screen width
On mobile devices viewport width is the same as screen width because mobile devices don’t allow you to change the size of your browser
Add the following to your
element
<meta name="viewport" content="width=device-width, initial-scale=1">
More info on the viewport meta tag
Tells the browser how to scale the web page
For a responsive site, the value width=device-width tells the browser to render the page at full size, whatever the size may be
The browser is rendering the page so that the viewport width is the actual width of the device (i.e., at 100%)
Tells the browser how to scale the web page when it’s first loaded on the screen (i.e., the zoom factor)
initial-scale=1 means that the page will be rendered at the size determined by the width attribute, and will not be zoomed in or out
If you use a number larger than 1, then the page will be zoomed to that level
initial-scale value only determines the size of the web page when it’s first loaded on the screen. Remember that your mobile device also gives users the ability to zoom in and out