The kilohertz (kHz) is a unit of frequency in the International System of Units (SI), equivalent to one thousand cycles per second or 1,000 hertz (Hz). It measures the number of oscillations or cycles of a periodic signal that occur within one second. The symbol for kilohertz is kHz. This unit is commonly used to express the frequencies of audio signals, radio broadcasts, and other types of electromagnetic waves within the audible and radio frequency ranges. In practical contexts, kilohertz is crucial for specifying the bandwidth of communication systems, the tuning frequencies of radios, and the sampling rates of digital audio equipment. In scientific and engineering fields, kHz is vital for analyzing signal processing, telecommunications, and the characteristics of various types of waves, ensuring precise communication and accurate measurement across a wide range of applications.