Spectrum sensing is a technique used in wireless communication to detect the presence of signals in a specific frequency range. It helps identify which frequencies are occupied and which are available for use. This is crucial for optimizing the use of the radio frequency spectrum, especially in environments with many devices competing for bandwidth. 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 based on the detected spectrum conditions. Effective spectrum sensing can lead to better communication quality and reduced interference among users.