Now the rubber hits the road, this is where the proof is in the pudding. There must be a miracle attributed to the Venerable: evidence that this person is, indeed, with God in heaven.
The miracle put forth is done so by the diocese in which the miracle took place. It is, itself, highly scrutinized and must be deemed without a natural explanation. In the case of John Paul II - although a bit different because of the waiving of the “waiting” period - a miracle attributed to him is the unexplainable curing of a cerebral aneurism. Part of the determination if the miracle will be credited to the Venerable is if all those involved were only praying for the Venerable’s intercession. In other words, they weren’t praying for the intercession of Mary or Archangel Raphael and so on.
Once the miracle is recognized by the Holy Father, the Venerable is called Bblessed. Venerable John Paul II becomes Blessed John Paul II and, according to Church teaching, Catholics are able to privately venerate the Blessed. Public veneration is still prohibited because in the normal timeline of this Canonization process, a second miracle is still needed.