[just2n]

If you want to learn more about this, the visual formatting model in the CSS 2.1 spec is very readable: http://www.w3.org/TR/CSS2/visuren.html.

If I were interviewing a candidate, I wouldn't expect them to be able to deeply recall most of that detail (though I'd expect them to be familiar with the basics). I'd accept an acknowledgement that floating an element takes it out of the flow, while using inline-block doesn't, as well as some further detail about what that means, what impacts/side effects it has on other elements and markup.