Spectrum sensing is a technique used in wireless communication to detect the presence of signals in a given frequency band. It helps identify which frequencies are occupied and which are available for use. This is crucial for optimizing the use of the radio spectrum, especially in environments where multiple devices operate simultaneously. By employing spectrum sensing, devices can dynamically access unused frequencies, improving overall network efficiency. This process is essential for technologies like cognitive radio, which adaptively adjust their transmission parameters based on the detected spectrum conditions. Effective spectrum sensing enhances communication reliability and reduces interference among users.