From a formatting behavior point of view, HTML elements can be divided into 2 categories:

► Block Element - Formatted as a rectangular block occupying the entire width of the parent content box. For example, <P> is block element.

► Inline Element - Formatted as a rectangular block joining other inline elements horizontally to form a line of inline elements. If the width of the parent content box is reached, it will be wrapped to start a new line. One or more lines of in-line elements become a block element. For example, <IMG> is an inline element.