What is meant by the Eighth Amendment’s guarantee that punishments should not be “cruel and unusual”?

The Eighth Amendment to the United States Constitution, part of the Bill of Rights, states: "Excessive bail shall not be required, nor excessive fines imposed, nor cruel and unusual punishments inflicted."

The phrase "cruel and unusual punishments" in the Eighth Amendment is interpreted to mean that punishments for crimes should not be unnecessarily harsh or degrading. The aim is to prevent the government from imposing punishments that are considered barbaric, excessively severe, or contrary to evolving standards of decency. The interpretation of what constitutes cruel and unusual punishment has evolved over time and is often influenced by societal attitudes and legal precedents.

Courts, including the Supreme Court of the United States, play a role in determining whether a particular punishment violates the Eighth Amendment. This includes assessing the proportionality of a punishment to the crime committed and considering whether the punishment goes beyond what is deemed acceptable by contemporary standards. The Eighth Amendment provides a constitutional limit on the types of punishment that can be imposed in the criminal justice system.