Default Promotions in Magento are split into two sections. Catalog Price Rules and Shopping Cart Price Rules. Catalog price rules refer to any promotion that applies to a product before you reach the shopping cart. An example of this would be '10% of X product' which can be found here on our demo site. http://www.liquidshopmagento.co.uk/somerset/model-shop/airfix-de-havilland-sea-vixen-faw-2-scale-1-48.html
Shopping Cart Price Rules are promotions that are added on when you reach reach the shopping basket. These can be promotions such as BOGO's, delivery discounts and unlike catalog cart rules, you can use voucher codes for promotions as they are added on at the shopping basket.