What is the difference between display: inline and display: inline-block?

A visual answer

Imagine a <span> element inside a <div>. If you give the <span> element a height of 100px and a red border for example, it will look like this with

display: inline

display: inline-block

display: block

Code: http://jsfiddle.net/Mta2b/

Elements with display:inline-block are like display:inline elements, but they can have a width and a height. That means that you can use an inline-block element as a block while flowing it within text or other elements.

Difference of supported styles as summary:

• inline: only margin-left, margin-right, padding-left, padding-right
• inline-block: margin, padding, height, width

display: inline; is a display mode to use in a sentence. For instance, if you have a paragraph and want to highlight a single word you do:

<p>
    Pellentesque habitant morbi <em>tristique</em> senectus
    et netus et malesuada fames ac turpis egestas.
</p>

The <em> element has a display: inline; by default, because this tag is always used in a sentence. The <p> element has a display: block; by default, because it's neither a sentence nor in a sentence, it's a block of sentences.

An element with display: inline; cannot have a height or a width or a vertical margin. An element with display: block; can have a width, height and margin.
If you want to add a height to the <em> element, you need to set this element to display: inline-block;. Now you can add a height to the element and every other block style (the block part of inline-block), but it is placed in a sentence (the inline part of inline-block).