CSS is the front end design of any HTML document. CSS is the thing when user visits a website then they see the content is arranging nice way. That can be possible using CSS, There is property of that. The property is the color piece of this declaration. It dictates which aspect of the selector will be changed visually. The value is what the chosen CSS property will be changed to. In our example, we are using the hex value of #000, which is CSS shorthand for "black."