It's the law, but which law-federal or state law? In the United states,there are different layers of laws. At the top is federal law,which Congress makes foe all people in the United States. Then each States makes laws about things in its territory. The laws that each state makes must not go against federal laws. Counties and town also make rules. A town many require that you have a license fo your bicycle,foe example. Here are some similarities and differences in state laws.