The purpose of this article is to present a Precision Agriculture (PA) review and the main elements of Internet of Things (IoT) ecosystem for PA- design and implementation. Thus, specific sensing technologies and sensor deployment are considered (fixed measurement station, mobile stations such drones and satellites). These sensing units are nowadays used to collect the data necessary to make the optimal decision regarding the plant requirements for a healthy growth, such as irrigation, fertilization and spraying of pesticides. The devices connected to the IoT network are constantly sending and receiving data based on long range communication protocols are providing information that can be used on the level of data science modules for PA for task optimization and cost minimization.