CSS allows you to do many things, but one neat thing are borders. Borders are useful when used in conjunction with the "width" and "height" attributes.

All paragraphs on this page are 200px wide and have a black border.

In addition, I've given the paragraphs 10 pixels of padding (spacing), so that it looks nicer.

You should know that the total width of the paragraphs is 220px because padding adds on to the width and height.

Later you will learn about margins and how to use them so as not to break your layouts.