The new series takes place in the future, in the year 2002, three years after the adventures of Taichi and the others.  Everyone is older, Takeru and Hikari are now in 5th grade, the same age Taichi and the others were when they had their adventures.  The older kids are now all in junior high and busy with clubs and studying.  Although the older kids make appearances in 02 (Taichi and Koushirou seem to have the most free time and are in almost every episode), the focus is mainly on Hikari and Takeru, along with three new kids, Iori, Daisuke and Miyako. 

In addition, there's a new enemy, the Digimon Kaizer, and lots of new Digimon and new evolutions using Digimental Armor.  With Armor Evolution, Digimon are no longer limited to just one evolution, they can evolve into many different Digimon, depending on which Digimental they use.