The Resting Ones were the people who had their bodies placed into suspended animation at Tranquil Repose on Necros. After their funerals were held, they would enter suspended animation until such time as a cure for their death was discovered and they could be returned to life.
The resting consciousness of a Resting One was constantly updated by the DJ who entertained them with music, developments with the universe, and messages from still living loved ones.
When Davros took control of Tranquil Repose, half of the Resting Ones were used to created the Imperial Daleks, a new generation of Daleks who would remain loyal to Davros. The others were converted into a source of food for planets that were facing famine. (TV: Revelation of the Daleks)