If you face a criminal charge, there is the potential you may end up in state or federal court. Each system operates slightly different, and you should understand the differences so you know what to expect.
The U.S. Courts explains the U.S. Constitution allows for two separate court systems with one in state governments and one in federal governments. Within each system, there are various types of courts that may handle only specific cases, such as appeals, juvenile matters or bankruptcy.
Judges in a state court may get their positions through appointment or election. In the criminal system, these courts will hear all criminal matters that fall under their jurisdiction. They have the final say on the interpretation of state laws, but you can appeal your case. You would first go to the Court of Appeals. You may then move up to the State Supreme Court and possibly the U.S. Supreme Court, which would then put your case in the federal system.
Only the president can nominate federal judges. Congress must approve the nominations. Most of the time when Congress confirms a judge, he or she will serve for life. Federal courts will often hear cases that only fall under their jurisdiction or cases that pertain to the constitutionality of a law. They also hear cases involving habeas corpus, admiralty law and disputes between states.
Federal courts also have an appeals process. The final stage is the U.S. Supreme Court. Do note that for both state and federal cases that appeal to the U.S. Supreme Court that the court does not have to hear those cases. It has the option to decide which cases it wants to hear.