Speed and frequency are two different properties of an electromagnetic wave:
Speed: The speed of an electromagnetic wave refers to how fast the wave propagates through a medium or through empty space, commonly denoted by the letter 'c'. In a vacuum, the speed of light, which is an example of an electromagnetic wave, is approximately 299,792,458 meters per second (or about 186,282 miles per second). The speed of light is constant and is one of the fundamental constants of nature.
Frequency: The frequency of an electromagnetic wave refers to the number of complete oscillations or cycles of the wave that occur in a second. It is measured in hertz (Hz), which represents cycles per second. For example, if a wave has a frequency of 100 Hz, it means that 100 complete oscillations occur in one second. Frequency is typically denoted by the symbol 'f'.
The relationship between speed (c), wavelength (λ), and frequency (f) of an electromagnetic wave is given by the equation: c = λf, where λ is the wavelength. This equation shows that the speed of an electromagnetic wave is equal to the product of its wavelength and frequency. As a result, if the frequency of a wave increases, its wavelength decreases, and vice versa. However, the speed of light remains constant regardless of the frequency or wavelength.