During the work, I tried to investigate in as much detail as possible what sensors are, how they work, and their division according to the principle of operation, output signal, and measured size. I explained how the sensors enable precise and reliable measurement of a wide range of quantities, depending on the needs of the system and applications. When applying sensors, I explained which industries depend on these components and what their role is in that process. Understanding the structure of sensors gives us a better insight into their structure, so I realized that the common component of every sensor is a sensor element that serves to detect a certain size or reacts to a change that occurs in the environment. In addition to the sensor element, there is usually a converter, an amplifier, a power supply, and an interface, and they all together form one functional unit. Part of the work covered the Internet of Things (IoT), i.e., the network infrastructure that enables sensors to be part of a global network and work together. In this way, the sensors exchange data with each other, perform certain functions, and at the same time have the possibility of remote control. In the chapter that spoke in more detail about wireless SMART sensors, I analyzed their application, construction, and data transmission technologies. I concluded that wireless SMART sensors are used in various industries, some of them are: medicine, agriculture, transportation, and smart homes and cities. With these sensors, data transmission is carried out using the Internet using various wireless transmission technologies (Wi-Fi, Bluetooth, NFC, Zigbee, LoRa, and Cellular), and therefore these sensors, in addition to the components already mentioned, must contain a microcontroller, a wireless communication module, an analog-to-digital converter, memory, and a signal processing device. In order to ensure the functionality and compatibility of sensors in smart devices and systems, certain standards must be respected, the most important of which are the IEC and IEEE standards, which are discussed in Chapter 4.4. As an example of the application of wireless SMART sensors, I chose smart houses that are based on and cannot function without sensors and smart devices. These are units that enable the user to remotely control various systems within the home and automate them, and as a result, they provide greater comfort within the home and improve the energy efficiency, functionality, and safety of the home. This chapter also describes the history of smart homes, their systems, data transmission, advantages and disadvantages, and concludes with the savings that smart homes bring to the user.