display: block;

  1. Can control height and width
  2. New line (line break) before and after

Examples: <p> and <h1>

display: inline;

  1. No control over height or width
  2. Sits next to other inline elements
  3. Does not make a new line (line break)

Examples: <span> and <a>

display: inline-block;

  1. Can control height and width
  2. Sits on same line as other inline elements

Examples: <img>

This h1 is a block element but this span is an inline element and the images below are inline-block elements.