From Paradise to Heaven

When Jesus was on the cross, He said to one of the one repentive criminals, He said to him, "Truly I say to you, today you shall be with Me in Paradise" (Luke 23:43 ). Until the death and resurrection of Christ, no one has entered into Heaven, so where are all the people (or the Souls of the people) who died previously?
The video provides gives a brief definition of the place called Paradise and the place called Heaven within the Biblical context.