Do they differ in just frequency and wavelenght ? Or there is more about it
They have various properties that differ, but the differences are quantitative, not qualitative, and there is no sharp boundary. The differences occur because of the difference in frequency. A wave that is a gamma ray in one frame of reference could be an x-ray if observed in a different frame.
An example of their different properties is that gamma rays are more penetrating, and are more likely to undergo Compton scattering rather than the photoelectric effect. The reason x rays and gammas were given different names is that originally nobody knew they were both part of the electromagnetic spectrum. The name "gamma" was simply a label used to classify them by how penetrating they were -- more penetrating than alphas or betas.