Morals define what is acceptable and unacceptable to a particular group of people/person.
What's acceptable to you may not be acceptable to me.
The reason why i used the word acceptable rather than good/bad is because nothing is inherently good/bad. It is the acceptability of things that defines one from the other as good/bad.
The diversity of our definition of good/bad is contingent upon so many factors (i.e. religion, culture, family beliefs/traditions, personal beliefs, etc.)
It is us where morals came from, and morals continually evolve as man's belief and rationale of things evolve.