CSS Display: Override The Default Display Value

//a common example is making inline <li> elements for horizontal menus

li {
  display: inline;
}

Changing an inline element to a block element, or vice versa, can be useful for making the page look a specific way, and still follow the web standards.

Setting the display property of an element only changes how the element is displayed, NOT what kind of element it is. So, an inline element with display: block; is not allowed to have other block elements inside it.