A Frequency Counter is an electronic device used to measure the frequency of an input signal. It counts the number of cycles of a waveform that occur in a specific time period, typically expressed in hertz (Hz). This tool is essential in various fields, including telecommunications, audio engineering, and electronics, where accurate frequency measurements are crucial. Frequency counters can display results in real-time and often come with features like averaging and statistical analysis. They are commonly used in conjunction with other instruments, such as oscilloscopes and signal generators, to analyze and troubleshoot electronic systems and signals.