Differences: size/weight obviously (the MacBook is really heavy for its size whereas the Pro model is very light for its size), material and build quality, graphic card (dedicated in Pro), performance (more powerful components in the Pro) and screen (choice of matte or glossy in the Pro).
Due to the weight and quality issues of the regular MacBook I'd recommend a Pro model (specificity a refurbished 2.2GHz for less ten 1500 USD) unless you're a road warrior and need something really portable/lightweight.