Kortaga is a system of penal servitude of the prison farm type in Imperial Russia.

Katorgas had been established in the seventeenth century in underpopulated areas of Siberia and the Russian Far East that had few towns or food sources.

Prisoners are sent to remote camps in vast uninhabited areas of Siberia—where voluntary laborers are never available in satisfactory numbers—and forced to perform hard labor.

Unlike concentration camps, "katorga" is within the normal judicial system of Imperial Russia, but both share the same main features: confinement, simplified facilities (as opposed to prisons), and forced labor, usually on hard, unskilled or semiskilled work.