I haven’t spend too long thinking about morals, but I have thought quite a bit about ethics, I think my view might be biased then, but here it is: Morals are just ethics with evolution mixed in.
If you think some things are moral, they can favor survival and/or procreation. For example, to mate for life is considered moral, because it helps your genes to spread no matter how poorly you age (your wife/husband is not going to run away with the younger choice because you stopped treating her/him like a queen/king).
Also, to consider some things immoral favors survival and/or procreation (for example to influence your spouse to think cheating is immoral, and punishing such immoral behavior, is something that favors spreading your genes, so much so that people often divorce cheaters and risk not having more children of their own, to help everyone else keep up the social culture of cheating being immoral).
This is how something downright unethical, like killing a human being, can be moral in certain cases, like for stealing food which had a death sentence right up until modern time all across the world. Those that steal food gets killed: this vastly improved the survival ability and procreation ability of the rest of society. That does not however mean it is ethically sound.
Morals are sort of like a sum game. If an action has 5 benefit and -1 drawback then the resulting sum is 4, and that is moral. So for example, killing one person to save 5 people, 5 minus 1 equals 4, so more good than bad comes from it, therefore it is argued as moral.
Ethics however, don’t cancel one bad with one good. If you kill one to save 5 then you killed someone no matter how many you saved, and so it is unethical.
PS: I follow the ethics point of view, killing is never good.