Explain the CSS box model and its elements.

The CSS Box model consists of the following items: Margin, Border, padding, and content. A margin represents the topmost layer that describes the overall structure. A border separates the margin and padding, or it can define the padding and content that surrounds it with a border. The background color affects the border. Padding is the space between the border and the content. It means if an element has the background color and that color will also fill in the padding.