The differences between values, morals and ethics is to provide behavioral rules. It may seem like splitting hairs, but the differences can be important when persuading others.
Values are the rules by which we make decisions about right and wrong, should and shouldn't, good and bad. They also tell us which are more or less important, which is useful when we have to trade off meeting one value over another.
You can have professional ethics, but you seldom hear about professional morals. Ethics tend to be codified into a formal system or set of rules which are explicitly adopted by a group of people. Thus you have medical ethics. Ethics are thus internally defined and adopted, whilst morals tend to be externally imposed on other people.
If you accuse someone of being unethical, it is equivalent of calling them unprofessional and may well be taken as a significant insult and perceived more personally than if you called them immoral (which of course they may also not like).