Both x rays and gamma rays are high energy electromagnetic waves.
Wavelength
They have wavelengths between 10 billionths of a meter and 10 trillionths of a meter. X rays have the second shortest wavelength and it can only get a little bit shorter, by switching to the gamma rays, which are the shortest.
Energy
Doctors and dentists use low does of x rays to form images of internal organs, bones, and teeth. This uses energy because there is energy be transferred from the x ray machine to the computer, where you receive the information. Medical x rays are produced by colliding high-energy electrons into a metal target, usually tungsten.
Frequency
They have one of the highest frequency ranges, and it gets just a little bit higher with gamma rays. They have wavelengths a little bit longer than gamma rays and its energies range from 100 eV to 100 KeV.
More Information
x rays and gamma rays are the most energetic electromagnetic waves. X rays penetrate easily through some materials such as fat and muscle, but not others such as bone, which makes them useful in medicine. KeV stands for: Kilo electron Volt.