The types of orders vary by field; in trading, for example, there are market orders, which are executed immediately at the best available price, and limit orders, which are only executed when a specified price is reached. There are also stop orders to protect the investor from large losses, and stop-limit orders to define the price more accurately. In e-commerce, the types of orders include regular orders, pre-orders, delayed orders, direct shipping, and subscription orders, each of which is used according to the desired purchasing and delivery method.