1, purchase order is a more concentrated production, sales surface is more extensive, the market needs of the commodities in the form of acquisition of large changes. Purchase of goods by the two sides of the industrial and commercial needs of production and marketing according to the market, issued a reference target, the industrial and commercial enterprises to sign a contract, pre-order. Industrial enterprises should be delivered in accordance with the conditions specified in the contract, commercial wholesale enterprises in accordance with the contract acquisition.
2, the implementation of the purchase of commodities, is more complex varieties and specifications, the market demand for commodities change faster. This type of goods to implement industrial self-sale, commercial purchase.
3, on behalf of the wholesale sales is a business enterprise by the industrial enterprises (or other business enterprises) commissioned a sales business. Before the sale of goods, the ownership of goods to the entrusted unit in the sale of goods, after the purchase procedures and settlement of payments.
4, joint venture joint sales which is a form of purchase and sale developed in recent years. This form is mainly used for commercial ordering, shopping.