Why is viewport necessary in web development?

The viewport is the visible area of a web page in the browser. It determines the size and scale of the content displayed to the user. Without it, pages could display incorrectly on different devices, from desktops to smartphones.

Its main purpose is to adapt the page layout to the device's screen size. Using the viewport meta tag, you can control the width and scaling of the content.

<meta name="viewport" content="width=device-width, initial-scale=1.0">

• width=device-width: Sets the viewport width equal to the device's screen width.
• initial-scale=1.0: Sets the initial zoom level when the page loads. The unit means no zoom (100%).

The use of viewport is closely related to responsive design technologies, such as CSS media queries, which allow applying different styles depending on the viewport size.