A supply chain is a system of organizations, people, activities, information, and resources involved in the movement of a product or service from the supplier to the customer. There are a number of synonyms for supply chain that can be used interchangeably, such as value chain, logistics network, distribution channel, procurement process, and inventory management. Each of these terms refers to a specific element of the overall supply chain process, with value chain focusing on the creation of value for the customer, logistics network referring specifically to transportation and storage of goods, distribution channel dealing with the mechanisms through which products are sold, procurement process emphasizing the acquisition of raw materials, and inventory management addressing the control and optimization of inventory levels.