A long-arm statute is a law that allows a court to exercise jurisdiction over an out-of-state defendant if that defendant has sufficient minimum contacts with the state where the court is located. This means that if a person or business engages in activities that connect them to a state, they can be brought into that state's court system, even if they reside in another state. These statutes are essential for ensuring fairness in the legal process, as they help uphold the principle that individuals should be held accountable in jurisdictions where they have significant ties.