If you are speeding down the highway at 65 mph and are stopped by the police and find out the speed limit is 50 mph, your ignorance of the posted speed limit is not a defense to a speeding ticket. Likewise, lack of knowledge of the laws of theft or murder do not make for a defense under our legal system in the United States. The principle is not limited to criminal or quasi-criminal activities. Even if you have little or no understanding of the civil law, you are still bound by its precepts.
If you are a genealogist, ignorance of the law can also have unforeseen consequences, it may prevent you from finding crucial information about your ancestors.
For example, in my own state of Arizona, the trial courts of general jurisdiction are the county Superior Courts. Each of Arizona's counties has its own Superior Court system, with the main courthouse usually in the county seat and a presiding judge. However, in Utah, just next door, the main trial courts are called District Courts and there are 39 courts in 8 districts in 29 counties. If I were to go through each of the states, you would quickly see that there is a total lack of consistency and no uniformity in the U.S. Court system.
Generally, there are various levels of court jurisdiction from small municipal courts, to justice courts and on to the trial courts of general jurisdiction, then appellate courts and finally the various states all have a supreme court. The variations in court procedures and jurisdictions makes for a tapestry of differences across the country. In addition, most all of the states have go through various adjustments and reorganizations of their court systems over the years. It may take some considerable research to find out the particular court system during different time periods in the state.
Why would you want to search court records? Think, probate, wills, civil lawsuits, naturalization of immigrants, divorces, child custody, adoptions, and many, many more topics. But if you don't have any idea how the courts are organized or their procedures in any give point in time, then how do you expect to find anything? Immigration records are a good example. I you are interested, you may wish to review the article, Legal History of Immigration in the FamilySearch Research Wiki.