Which CSS property is used to set the space between the borders of an element and its content?

The property that sets the space between the borders of an element and its content is padding. Padding creates an inner space that pushes the content away from the edges of the element's border, allowing for a better visual layout by preventing the content from sticking directly to the edges. This is crucial for enhancing readability and aesthetics in web design.

Margin is used to create space outside of an element's border, affecting the distance from other elements. Border-spacing applies specifically to the space between table cells, not general elements. The term “spacing” isn't a valid CSS property and would not affect the layout as intended. Thus, padding is the correct choice as it directly modifies the space within the element, ensuring that content is visually distinct from its border.