CodeHS Advanced HTML and CSS Practice test

The filter property in CSS is designed to apply visual effects to elements on a webpage. It allows web designers to manipulate the appearance of images and other elements through various graphical effects such as blurring, changing brightness, contrast adjustments, grayscale filters, and creating other stylistic modifications.

For instance, using filter: blur(5px); on an image will soften the image by a specified radius, giving it a blurred appearance. Similarly, applying filter: brightness(150%); can enhance the brightness of an element, making it more prominent.

This property does not modify the layout of a webpage, add shadows, or change font sizes directly. Each of those functionalities is served by different CSS properties, such as margins and positioning for layout, box-shadow for shadows, and font-size for text size alterations. Hence, the function of the filter property is specifically aimed at visual effects rather than layout structure or text manipulation.