Why does image use display: inline but behaves like an inline-block element

Question

Why is the default display style for image inline instead of inline-block?

Is there any difference between inline and inline-block for img elements, from what I can

Answer 1

IMG is an Inline & Replaced element.

A replaced element is any element whose appearance and dimensions are defined by an external resource.

As per W3C

The IMG element has no content; it is usually replaced inline by the image designated by the src attribute, the exception being for left or right-aligned images that are "floated" out of line.

Check this link for more http://reference.sitepoint.com/css/replacedelements