LoRaWAN is a low-power broadband network technology that is suitable for IoT applications that require long-distance communication and extended battery life. The main characteristic of the LoRa system is the need for long-term operation with extremely low energy consumption. LoRaWAN is a key technology for implementing the Internet of Things (IoT) concept because it is easy to use, supports low-cost, low-power end devices, and provides high-range two-way data communication. The application of LoRaWAN technology is very widespread around the world with a tendency of increasing dominance in relation to similar technologies that enable the exchange of messages over longer distances in IoT networks. This paper describes the operation of LoRa technologies on the network and data layers, the classes of end devices and the most important transmission parameters, which include the spreading factor, transmission power, coding rate and transmitted data size. A comparison of LoRaWAN technology with other communication technologies is also described, and the reasons why LoRa is today one of the best technologies for realizing sensor and IoT networks that require communication over longer distances are presented. In the last part of the paper, the measurement of the instantaneous current consumption of the communication module of the LoRaWAN device is described. In the measurement process, different configurations of transmitter parameters of LoRaWAN devices were used. The measurements confirmed the significant influence of the spreading factor and transmission power on the instantaneous current consumption of the LoRaWAN device. The speading factor and the size of the transmitted data significantly affect the transmission time, while the transmission power affects the increase in current consumption. This means that it has been proven through measurements that with an increase in transmission power, the power consumption used by the communication module when sending a message also increases, and with an increase in the transmission factor, the duration of increased power consumption increases compared to the consumption in periods when the LoRaWAN device does not transmit messages. It was also confirmed through the conducted measurements that the properties of the analyzed LoRaWAN communication module are reflected in very low power consumption and long battery life. It is to be expected that the future development of circuit components of LoRa technology will contribute to an even greater reduction in the energy consumption of LoRaWAN devices, which will improve the application of LoRaWAN technology in various branches of industry.