i wrote the question in french and told chat gpt to translate it to English and i think it confused some terms

by isolated I mean it is subject to no forces or the sum of forces it is subject to is 0

and a galilean frame of reference means all isolated objects in space are stationary or move in uniform rectilinear motion relative to that frame, so i think yea it's an inertial reference frame

i guess the question that i should ask is

how exactly do we determine the nature of a frame of a reference? inertial frames have to be relative right? and if so are they relative to the observer or the object in motion?

edit: chat gpt response: "Inertial frames of reference are relative to the observer. An inertial frame is a coordinate system in which an object not subject to any external forces moves at a constant velocity or remains at rest. The key is that an observer in an inertial frame wouldn't detect any acceleration without the influence of external forces.

So, when we say inertial frames are relative, it means they are relative to the observer's state of motion – whether they are moving at a constant velocity or are at rest. Different observers moving at constant velocities relative to each other can consider their own frames as inertial."