The Digivice 01 allows you to scan Digimon and discover everything about their data - which can be uploaded to your Digimon. If you have two or more of them, you can jogress your Digimon together. However, the Digivice 01 is not used to evolve Digimon in any other ways.
Demon's castle was once long ago the home of the God of Digimon, who governed the world. However, he hated interference from humans, so he created a seal that prevented any humans from entering his castle. God left, but the seal remained...and Demon moved in. But in the event fo a crisis that Digimon alone could not solve, God had created the Five V-Tamer Tags. The Tags were called Earth, Sea, Spirit, Sky, and Iron, and they were scattered around Folder and set so that Digimon could not touch them. When Demon learned of Taichi's plan to gather the Tags, he set a Perfect to guard each Tag. These are the Tags, their guardians, and the Digimon family they had marked on them:
The Tag of Earth
The Tag of Earth was the Nature Spirits Tag, and was guarded by Triceramon.
The Tag of Sea
The Tag of Sea was the Deep Savers Tag, and was guarded by Marine Devimon.
The Tag of Spirit
The Tag of Spirit, or Illusions, was the Nightmare Soldiers Tag and was guarded by Vamdemon.
The Tag of Iron
The Tag of Iron was the Metal Empire Tag and was guarded by Metal Greymon.
The Tag of Sky
The Tag of Sky was the Wind Guardians Tag and was guarded by Cockatrimon and Kuwagamon, who jogressed into Megadramon and then with a Jureimon into Deathmon.