“…nor shall any State deprive any person of life, liberty, or property, without due process of law…”
In broad strokes, the Due Process Clause of the Fourteenth Amendment requires the government to act legally whenever it tries to limit one of your constitutionally-protected freedoms. The text of the clause is nearly identical to a similar clause found in the Fifth Amendment, and together they require states and the federal government to act fairly and according to law whenever government actions may affect a person’s life, liberty, or property. Under this principle, a person could not, for example, be jailed indefinitely without an opportunity to be heard by a judge.
But the Supreme Court has also recognized a “substantive” dimension to the Due Process Clause. Under this complex body of case law, the justices have recognized that the notion of due process also requires the government to respect certain fundamental rights found both in the text of the Bill of Rights and other parts of the Constitution. The Supreme Court relied on this understanding to recognize that the personal right to privacy, which isn’t explicitly mentioned in the Constitution, is nonetheless protected by it from government intrusion. And from that same principle the Court later recognized, in the landmark case Roe v. Wade, that a woman has a constitutional right to choose to end a pregnancy.
Because of the breadth and intricacy of these and other court decisions, the Due Process Clause of the Fourteenth Amendment is one of the most studied and scrutinized in all of constitutional law. As with other parts of the amendment, the provision helps ensure fundamental fairness and stands as a bulwark against government overreach.