A mutation is a change in the genetic code of one allele of your genetic code. ( rarely does mutation affect both alleles ) Most mutations are neutral, some are deleterious, but sometimes a mutation...
Those that increase your health, your survival, your ability to have children and of course too many other benefits to name, here. Generally mutations are the key to natural selection. Beneficial...
What else would they be? If something mutates, the results are either beneficial and do something good; or they are harmful. Even if you were to try and claim the result "neutral", most would argue...