Typically awls have a shorter, larger diameter shaft with a steeper, more abrupt tip grind designed for piercing. Where as straight picks tend to be slimmer in diameter and a gradual taper ground on their end for easy of transition / separation; more like a wedge. Awls typically also have a more ball type handle designed for palming, where as a pick typically has a more screw driver type handle for prying and delicate work.
A number of manufactures tend to blur the lines, especially those that make general purpose (IE non auto or machining specific) tools.