What is Prisoners' Rights?

Legal Definition
The rights of civilian and military prisoners are governed by both national and international law. International conventions include the International Covenant on Civil and Political Rights; the United Nations' Minimum Rules for the Treatment of Prisoners, the European Committee for the Prevention of Torture and Inhuman or Degrading Treatment or Punishment, and the Convention on the Rights of Persons with Disabilities
-- Wikipedia
Legal Definition
Federal and state laws govern the establishment and administration of prisons as well as the rights of the inmates. Although prisoners do not have full Constitutional rights, they are protected by the Constitution's prohibition of cruel and unusual punishment (see Amendment VIII). This protection requires that prisoners be afforded a minimum standard of living. Prisoners retain some other Constitutional rights, including due process in their right to administrative appeals and a right of access to the parole process. The Equal Protection Clause of the 14th Amendment has been held to apply to prison inmates. Prisoners are therefore protected against unequal treatment on the basis of race, sex, and creed. Additionally, the Model Sentencing and Corrections Act provides that a confined person has a protected interest in freedom from discrimination on the basis of race, religion, national origin, or sex. Prisoners also have limited rights to speech and religion.

State prisoners have no rights to particular classifications under state law. Courts are extremely reluctant to limit the discretion of state prison officials to classify prisoners. (Classification, as it is used here is meant to describe the custodial classification of a prisoner once he or she is convicted -- i.e.: maximum vs. minimum security, solitary confinement, etc.)

Congress has given federal prison officials full discretion to control prisoner classification as affecting conditions of confinement. Generally, such matters are left to the control of the Federal Bureau of Prisons.

Courts tend to give deference to prison officials regarding prisoners' rights. So long as the conditions or degree of a prisoner's confinement are within the sentence and not otherwise violative of the Constitution, the due process clause does not require judicial oversight. For prison regulations that do impinge on inmates' constitutional rights, the strict scrutiny test does not apply. Rather, the rational relationship test is used (the lowest level of judicial scrutiny -- the test is whether there is a rational relation to a legitimate state interest).