1. What is subject matter jurisdiction?
It’s the authority of a court to hear cases of a particular type or cases relating to a specific subject matter

2. What is the difference between personal jurisdiction and in rem jurisdiction?
The differences between both are that In rem jurisdiction is jurisdiction over a specific thing for the purpose of adjudicating the rights to that thing. For example the government seizes a ship claiming that it has been transporting drugs. The court whose jurisdiction includes the location of a ship has jurisdiction to adjudicate the issues relating to seizure of the ship, even if the court does not have personal jurisdiction over the owners of the ship.
Quasi in rem jurisdiction is really a limited form of personal jurisdiction. Utilizing quasi in rem jurisdiction quasi in rem jurisdiction has been severely limited by the courts because it raises serious due process concerns.

3. When does a court have personal jurisdiction over a party to a lawsuit?
Personal jurisdiction, or in personam jurisdiction, refers to the power of a court to enter a binding judgment against a person or other legal entity. A court must be able to exercise personal jurisdiction over a party in order for that party to be bound by an order of the court.
The Fourteenth Amendment grants the right to not be compelled to defend a lawsuit in a remote jurisdiction unless a party’s actions have made it fair to hale that party into court. A court’s exercise of jurisdiction over a party must not offend traditional notions of fair play and substantial justice. The court asks whether a party reasonably should have anticipated that his actions might result in the forum state exercising personal jurisdiction over him in order to adjudicate disputes arising from those actions. In addition, due process requires that process be served upon a party before that party can be subject to personal jurisdiction.
The court may consider a number of factors in such a determination. Purposeful acts of the defendant need not take place within the forum state, provided that those acts create a substantial relationship with the forum state. In order for personal jurisdiction to be valid, however, the state must have a suitable long arm statute and the party must be given notice.

4. What is a long-arm statute?
A state law that allows the courts of that state to claim jurisdiction over decide cases directly involving Persons outside the state who have allegedly committed torts or other wrongs inside the state. Even with a long-arm statute, the court will not have jurisdiction unless the person sued has certain minimum contacts with the state.

5. Why do states have them?
In the United States, some states' long arm statutes refer to specific acts, for example torts or contract cases, which a court may entertain.