Frequency refers to the number of waves that pass through a specific place in unit time.
In other words, frequency is the number of wave crests that pass through a certain spot in a second.
The highest frequency is in the electromagnetic spectrum, gamma rays have the minimum wavelength and highest frequency. They have a frequency of approximately to .
Following radioactive decay, the nucleus of some radio nuclides emits a packet of electromagnetic energy called ‘photon’ known as a gamma ray.
The highest energetic photons in the electromagnetic spectrum are gamma photons.