Catholics believe that Jesus rose from the dead after being crucified, that this is a real event in history and has been verified by sacred scripture. Later, St. Paul would also write about the Resurrection (1 Corinthians 15:3-4)
However, Resurrection does not mean only the resuscitation of a dead human body back to its previous form, but, rather, as the Catechism tells us:
Christ’s Resurrection is essentially different. In his risen body he passes from the state of death to another life beyond time and space. (CCC 645-46).
In short, this Jesus is the same Jesus, but he looks different to the disciples. Nobody was a witness to how Jesus came into this new way of real life, so we know not how this happens physically, but we hold that “the Resurrection was an historical event that could be verified by the sign of the empty tomb and by the reality of the apostles’ encounters with the risen Christ.” (CCC 647)