Without Clearfix

This image is floated to the right. It is also taller than the element containing it, so it overflows outside of its container:

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus imperdiet...

With Clearfix

We can fix this by adding a clearfix class with overflow: auto; to the containing element:

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus imperdiet...