The viewport is the visible area of a webpage on a device's screen. Depending on the size and resolution of the screen, the viewport dynamically adjusts. The viewport is especially important in responsive web design as it controls how content is displayed and scaled across different devices. To define the viewport and ensure optimal content display, the <meta> tag is used in the HTML header. A typical code example for defining the viewport is:
<meta name="viewport" content="width=device-width, initial-scale=1.0">
width=device-width: Adjusts the viewport width to match the device width.
initial-scale=1.0: Sets the zoom level to a default value of 1.
Proper use of the viewport ensures that content is readable on mobile devices without unnecessary scrolling.