Today, every country has laws. In most cases, different parts of the government writes different laws. So there can be quite a large set of laws which set out what you can and cannot do. Criminal law covers the really serious things like violence or stealing. These are very severely punished by the government and could mean time in jail.
Many people seem to think that there is only criminal law.
That is not true. In fact, there are more non-criminal laws than criminal laws. That doesn't mean that they don't have to be followed. It just means that in these cases, the government will not take care of bringing your case to a judge for you. You have to do it yourself.