Overflow set to visible

This is a "parent" box.
This is a "child" box whose contents are overflowing the borders of its parent. When content such as this overflows its box, you must decide how you want the browser to handle it. That is the purpose of the overflow and clipping properties.

Overflow set to hidden

This is a "parent" box.
This is a "child" box whose contents are clipped because the "hidden" value of the overflow property was applied.

Overflow set to scroll

This is a "parent" box.
This is a "child" box whose contents can be viewed by using the scroll bars created by the "scroll" value for the overflow property.

Overflow set to auto

This is a "parent" box.
This is a "child" box whose contents are scrolling because the overflow property has been set to "auto".