Responsive sites can have a mixture of fluid and absolute measurements.

Responsive web design aims to create websites that provide optimal viewing experiences across a wide range of devices, from desktop computers to mobile phones. To achieve this, developers often use a mix of fluid and absolute measurements.

Fluid measurements, typically expressed in percentages or viewport units, adjust the size of elements relative to their parent container or the viewport. This allows layouts to adapt dynamically to different screen sizes. For example, using a width of 50% for a div means it will always take up half of the available width, regardless of the device being used.

On the other hand, absolute measurements, which can include pixels or fixed units, can be useful for certain design elements that need to maintain a specific size regardless of the site's responsive behavior. These might include icons or images where precise dimensions are important.

By combining fluid and absolute measurements, developers can achieve both flexibility and control in their layouts. This hybrid approach allows for more creative and functional designs that work well across various devices, making it a core practice in responsive design.