1) The english word "law" refers to limits upon various forms of behavior.
2) some laws are descriptive: they simply describe how people, or even natural phenomena, usually behave
3) some laws are prescriptive - they prescribe how people ought to behave
4) Prescriptive laws
5) through the instruction of family and teachers, the advice of friends, and our experiences in dealing with strangers
6) precise penalties
7) Governments use a system of courts backed by the power of police to enforce these laws