Wireless Sensor Network (WSN) now days become a promising technology in which the set of sensor nodes are installed to form a network and these sensor nodes send data to a storage centre called sink or off shore base station. This data helps in revolutionizing many sensor network based application areas like military, sciences, automobile industry etc. Further, there exists another category of this broad field that is Underwater Wireless Sensor Network abbreviated as UWSN in which sensor nodes are deployed under the water and they use acoustic signals for communication and data transmission. In this paper, some concepts and routing protocols for both WSN and UWSN are presented. Also various issues are highlighted; those can come during communication in both the technologies. Further, issues during routing protocols design those plays important role for communication in establishing and maintenance of network are also discussed.