The most concise definition/explanation of the Resurrection can be found in the Glossary  of Joseph Ratzinger’s (Pope Benedict XVI) JESUS OF NAZARETH, Part Two) Ignatius Press

“The entrance by Jesus, following his death on the Cross, into an entirely new form of life that lies beyond the order of natural biological generation, resuscitation, and  dying and that includes a transformed bodily dimension of existence, possessing physical and spiritual aspect. (Mt. 22:30; 1 Cor. 15:42-44, 50-54; Luke 24:39; Jn 20:24:24-27)

“The Resurrection is the Father’s vindication of Jesus’ divine sonship and validation of the believer’s faith in Jesus’ redemption of sinful humanity.”  (Acts 2:24; Rom.1:4; 1 Cor. 15: 14, 17)

“It is also the pledge of  ‘first fruits’ of a general resurrection, the beginning of a new kind of humanity to be realized in the age to come.”  (1 Cor 15:23)

“The Resurrection of Jesus in not the mere passing of a spirit into the next life or a miraculous resuscitation to mortal existence, as with Lazarus.  It is an entirely new mode of bodily existence.”

For a spiritual and scholarly expansion, see chapter 9, Jesus’ Resurrection from the Dead.