Pardon, amnesty, absolution in their legal and ecclesiastical senses mean a remission of penalty or punishment.
Pardon, which is the comprehensive term, is often ambiguous; it denotes a release not from guilt but from the penalty imposed for a transgression of secular or spiritual law. Thus in civil and military affairs a pardon usually implies a release from prison, or from the payment of a fine, or from a sentence of death, and permission to go scot free, though not acquitted, but the term may suggest as a cause either executive clemency or the undoing of a judicial wrong.
When a pardon is extended to an entire class (as an insurgent group) or to an entire community, it is called an amnesty.
Amnesty often suggests not only that past offenses will go unpunished, but that they will be forgotten. When, in ecclesiastical use and especially in the use of the Roman Catholic Church, a pardon is extended for sins confessed and atoned for according to the laws of the Church, it is specifically called absolution when it implies that the eternal punishment for sin has been remitted in the sacrament of penance.