When you open a website, HTML elements are rendered using a "box model".
Each elements is drawn/displayed inside a box, though we rarely look at
it. In fact, this <p> element has its own box.
In short words, each box is delimited by its border. The distance between the box and its content is called the padding, and the distance between the border and the closest element is called the margin. The three of them border, margin and padding, have top, bottom, left and right specifications.
