Domain Name System-DNS is a key service of the Internet. Without DNS, we cannot use any useful Internet applications. At the beginning of the Internet, email or file transfer applications were provided. DNS provides key service to them-resource discovery. Nowadays, there are broad range of software making use of DNS as basis of their application. In this paper, we explain the evolution of DNS, how DNS works and recent activities including operational issues. Then, we describe EPC network which make use of RFID to bridge real world and the Internet, and how DNS helps to organize EPC network.