Frequency Shift Keying (FSK) is a method of digital communication that conveys data by varying the frequency of a carrier wave. In FSK, different frequencies represent different binary values, typically using two frequencies for binary '0' and '1'. This allows for reliable transmission of data over various communication channels. FSK is commonly used in applications like modems and radio transmissions. It is robust against noise and interference, making it suitable for environments where signal quality may fluctuate. By changing frequencies, FSK ensures that the transmitted information can be accurately received and decoded by the intended device.