system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How are electrical devices onboard the ISS grounded?
gpt
It is not grounded if you use the meaning connected to the earth. A connection to earth is not required for the electrical system but is a practical way to have a common reference level and possible return part of the electrical system.  


The frame of ISS will be what is defined as ground ie 0 voltage.  This is exactly how it is done in a car where you do not have anything conductive that connects it to the ground.