A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information. wikipedia.org

Active listening is a communication technique that requires the listener to feed back what he hears to the speaker, by way of re-stating or paraphrasing what he has heard in his own words, to confirm what he has heard and moreover, to confirm the understanding of both parties. wikipedia.org

Customer service is the provision of service to customers before, during and after a purchase. wikipedia.org