Jurisdiction
When you are trying to determine which law applies to you, something called “jurisdiction” is very important. Jurisdiction can mean more than one thing in the legal context, but for our purposes here, think of jurisdiction as which governmental authorities have power over your behavior.
For example, when you are driving down the road in Iowa, the state of Georgia does not get to decide how fast you are allowed to drive, because Georgia does not have authority over the roads in Iowa. When you are renting an apartment in Des Moines, your landlord is not bound by rental rules put in place by the Dubuque City Council, because the Dubuque City Council does not have authority to make rules for landlords in Des Moines.
The examples above are easy – they are based on location. But in some cases, location itself does not cover it. You could be in Sioux City, which is in Woodbury County, which is in the State of Iowa, which is in the United States of America. Now, instead of relying solely on location, you need to think about the situation you are trying to address. In some cases, multiple levels of government may have some say over your behavior. For example, if you sold drugs, you could violate laws made by the State of Iowa and the United States of America. When it comes to paying your federal taxes, you need to follow both United States statutes and IRS regulations.