system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: When transferring money from one bank to another digitally, what exactly is being transferred?
gpt
Its trading IOUs

All your bank account really is, is the bank saying they 'owe' you your balance whenever you'd like it. And of course, you trust them to pay you when you want it.

All this does is shift that. Lets say you transfer $100, the other bank now has an IOU you for $100, and your original bank takes $100 off their IOU to you.