I know some of you are asking what Ap stands for, I don;t know for sure but thats not what you need to know. AP is like the 8 types of Spieces Exp in Digimon World DS, you need it to evolve to certain digimon, It goes in Dragon, Beast , Bird, Insect, Beast etc you can get this AP by putiing your digimon in an training area tht gives it. Example the Valcano like are gives dragon. Beach one Gives water. Just look for the training areas that most resemple the speices farms of Digimon World DS to get the AP tyoe you want.
There are 11 types of Experience that can be attained from training the digimon which have been referred to as AP in previous posts: The 8 Family types: Dragon, Beast, Bird, Water, Insect/Grass, Machine, Darkness, Holy The 3 Attribute types: Vaccine, Data, Virus
There are specific cages to raise each of these 16 statistics, though the cages that you can use at the beginning can also raise them. For instance, the Minigym can increase Machine, while decreasing Bug/Plant, and the Vacant Lot does the reverse. Unfortunately, outside of the small text notices you get when a digimon has trained up in these experiences, it does not appear as though there is an in-game counter for them.
AP in-game refers to elemental resistances, but is not used for any evolution requirements. They are Heat, Cold, Lightning, Light, and Dark.