In a world, where the population is constantly increasing, agricultural productivity must be high to feed people. One of the most important factors affecting yield is irrigation. However, today various degrees of water scarcity are experienced in different parts of the world. Considering that water scarcity affects a large population, one of the measures to be taken in this regard is to prevent inefficient irrigation. The technical possibilities offered by technology have enabled the development of smart irrigation applications. In smart irrigation systems, first, data are obtained such as soil moisture status, which are necessary for determining the water requirement of the plant using methods such as sensors, cameras and remote sensing techniques. Then, the obtained data are transmitted wirelessly by methods such as internet of things or radio frequency, and the transmitted data are evaluated by various decision support systems and decisions can be made for the best irrigation management. In this way, irrigation efficiency is increased, contributing to plant productivity, protecting water resources by preventing inefficient water use, and preventing negative effects such as soil erosion, salinity, and loss of soil fertility. In this study, the benefits of smart irrigation applications and the technologies used in smart irrigation applications are explained with case studies and technical details.