Convict

A convict is "a person found guilty of a crime and sentenced by a court" or "a person serving a sentence in prison". The word is sometimes abbreviated as "con". After a conviction, convicts often become prisoners in a prison. People convicted and sentenced but not sent to prison are not usually called "convicts". An ex-convict (or short: ex-con) is a person who has been let out of prison.
In past centuries many convicts were send to penal colonies. Many British convicts were sent to the Thirteen Colonies as cheap workers, but that stopped after the War of Independence. After this, convicts were transported to Australia in 1788, the very start of European settlement. They were used as cheap workers. Transportation was stopped in 1868. British convicts were also sent to Canada and India. 
France also sent convicts to French Guiana and New Caledonia, and Russia sent them to Siberia.