From
here:
<blockquote><i>Designed and constructed in secret, the Death Star is the brainchild of the sinister Grand Moff Tarkin, governor of the Imperial Outland Regions. On board the Death Star, there are hundreds of prison levels capable of detaining entire populations. Metal cells line the prison levels like dark hives, encasing prisoners inside small black rooms of thick armor plate. Soundproof and escape-proof, the cells grip their prisoners with hopelessness and hide grim scenes of illegal interrogation and torture.
[...]
The completed Death Star is powered by a hypermatter reactor and is capable of destroying an entire planet with its prime weapon, a horrific superlaser. This abomination is the galaxy's ultimate weapon, and the greatest symbol of the Emperor's absolute power. Thousands of turbolaser battery emplacements speckle the rugged surface of the battle station, designed to defend it against capital ship assaults. Countless hangar bays house TIE fighters, shuttles, and other combat and transport craft.</i></blockquote>