Amnesty refers to a blanket overlooking of an offense by the government, with the legal result that those charged or convicted have the charge or conviction wiped out. Amnesty is usually granted because the war or other conditions that made the acts criminal no longer exist or have faded in importance.
Amnesty is often granted after a revolution or civil war when the victorious side extends amnesty to the losers. For example, amnesty was given to Confederate officials and soldiers after the Civil War, and has been granted to illegal aliens at times to allow them to stay legally in the country. Amnesty differs from a pardon because amnesty is the abolition and forgetfulness of the offence, whereas a pardon is forgiveness. A pardon is always given to an individual who hs been convicted, amnesty may be granted to a group or class of people who may or may not have been convicted of an offense.