Cascading styles are applied to elements and to classes and ids to establish a design. The widths of the navigation column and side-bar are fixed, allowing the content column to vary with the page size. This is referred to as a fluid design.

This image is completely irrelevant to the topic of this page except that it allows us to illustrate how floats work. The img element is styled to float left, which flows text around it to the right. As text continues, it will eventually flow back to the left margin, beneath the image.

It takes quite a lot of text to get that far, and you are probably getting tired of reading this content, but with a little patience you have now seen how the text does indeed flow back to the left margin. Did you really read all of this? I became bored just writing it.