A spectrum analyzer is an electronic device used to measure and display the frequency spectrum of signals. It helps visualize the amplitude of signals across different frequencies, allowing users to identify and analyze various components within a signal. This tool is essential in fields like telecommunications, audio engineering, and broadcasting, where understanding signal quality and interference is crucial. Spectrum analyzers can be either analog or digital, with digital models offering more advanced features such as real-time analysis and data storage. They are commonly used to troubleshoot issues, optimize performance, and ensure compliance with regulations in systems involving radio frequencies, audio signals, and wireless communications.