Mutants are beings that are typically morphologically similar to humans, however, some of them do have biological differences.
Typically, mutants are identical to humans. However, some mutants do have a physical mutation that causes them to have an abnormal appearance. Some physical mutations, such as Warren Worthington's wings, are easy to conceal while others, such as the reptilian appearance of Victor Borkowski, cannot be concealed.
One major difference between mutants and humans is that mutants are less likely to contract illnesses like colds, fevers, or even cancer. However, mutants are more likely to have emotional and mental disorders which can prove to be very dangerous since their powers can get out of hand when they are not in a reasonable mental or emotional state.
Mutants are evolved from humans but the two are different species. Mutants tend to live with humans, although some mutants communities have been established.
Mutants have the same society and government as humans.
Each mutant has their own set of abilities.