What does the term "viewport" refer to in web design?

In web design, the term "viewport" specifically refers to the visible area of a web page in the browser. This is the section of the web page that users can see on their screen at any given time, without having to scroll. Understanding the viewport is crucial for responsive web design as it helps designers and developers to create layouts that adapt to different screen sizes and resolutions, ensuring that content is accessible and visually appealing across a variety of devices, such as desktops, tablets, and smartphones.

The size of the entire web page is not the viewport; rather, it encompasses the entire content that may extend beyond what can be seen at once. Hidden elements of a web page may refer to components that are not currently visible on the screen due to the viewport's dimensions but do not inherently define what the viewport is. Loading speed pertains to how quickly the web page appears, which, while important for user experience, is unrelated to the definition of a viewport itself.