A marketing channel is the set of activities needed to move goods from production to consumption. There are direct and indirect marketing channels. Channel design involves developing new channels or modifying existing ones based on customer needs, objectives, and alternatives. Members in marketing channels include merchants who buy and resell goods, agents who search for customers but don't own goods, and facilitators who assist distribution. Designing a channel involves analyzing customer service levels, establishing objectives, identifying alternatives like wholesalers or retailers, and evaluating the alternatives based on factors like market preferences, product characteristics, and company resources.