The D-terminals were small handheld computer units. The D-terminals were used for sending and receiving emails among other things. However most importantly they were able to hold the digiegg data allowing easy storage and use of them. Each new DigiDestined were granted one when they received their partner and first digiegg. The original DigiDestined, like Tai however seemed to already had one.
The Digi-Eggs were created by Azulongmon and the other guardians of the DigiWorld for the new DigiDestined, so they could Armour Digivolve their partners to beat the Digimon Emperor’s to stop the his Control Spires from taking over the digital world since the digimon couldn’t digivolve.
