The filter CSS property allows you to apply visual effects and image adjustments to elements. It provides a way to manipulate the appearance of images, backgrounds, and even text. The filter property accepts various filter functions, such as blur(), grayscale(), brightness(), contrast(), saturate(), and more.

For example, filter: grayscale(50%); will render an element with a 50% grayscale effect, making it appear partially black and white. The filter property is a powerful tool for creating unique visual effects and enhancing the visual aesthetics of web content.