Software Defined Radio (SDR) is a radio communication system that uses software to control the hardware components of a radio device such as amplifiers, filters, and modulators to transmit and receive signals in a flexible and adjustable manner. It requires specialized skills in software engineering, radio frequency (RF) design, digital signal processing (DSP), and programming. SDR has gained popularity in recent years due to its versatility, cost-effectiveness, and ability to support multiple wireless communication standards. It is commonly used in military communication, amateur radio, and wireless research and development.