Somatic mutations are genetic alterations that occur in non-germline cells, meaning they are not inherited but acquired during an individual's lifetime. These mutations can result from environmental factors, such as UV exposure or chemical agents, or occur spontaneously during cell division. Somatic mutations are often associated with cancer and other diseases, as they can lead to uncontrolled cell growth or loss of normal cellular functions. In contrast to germline mutations, somatic mutations are not passed to offspring but can have significant health implications for the individual.