How can Digimon come into real world? As we know, Digimons are digital monsters made of Data in the Computer.
So in Digimon Adventure 01 and 02, all the Digimons come to the real world for a mission. But if they are just a piece of data, then how can they actually come out of the computer and take form?
Data needs a medium to compile and take form and the real world does not provide that medium, it only happens in devices that understand the data.
I remember in Digimon Adventure 2 there being a gate between the Digital World and the Real World which has a "corridor" where anything is possible.

BlackWarGreymon sacrificed himself to protect the Gate which when Mytoismon tried to break though it from the Real World ended up getting trapped in this corridor because of the seal BlackWarGreymon made, this is were we see the Digidestined able to have their partners assume every evolution form at the same time, as the battle continued Mytoismon was pushed back into the Digital World and the multiple forms disappear when they enter the Digital World probably because of Data Limits in the Digital World.

I would assume all travel between the 2 worlds is done though this Gate and "corridor" where the "corridor" is used to make digimon real and turn people into data and some objects into digimon (as seen in Frontier with the trains), the Gate itself probably doesn't have a fixed point.