X-rays and γ-rays are both electromagnetic radiations with similar properties (they propagate the same way, have high ionizing ability, and similar absorption behavior). The "main difference" is how they are produced: - X-rays → produced by interactions involving electrons outside the nucleus (e.g., in an X-ray tube when fast electrons hit a metal target). - γ-rays → produced by processes inside the nucleus (e.g., during radioactive decay when an unstable nucleus releases excess energy)