What does model.to(device) return and where is the documentation for it?

Question

I found documentation for models but not the specefic api documentation for model.to().

ChatGPT had told me conflicting info. that it returns a copy of the model and also that it returns a reference to the model.

I'm trying to understand this code:

modelBigram0 = BigramLanguageModel(vocab_size)
modelBigram1 = modelBigram0.to(device)

If I had the documentation for model.to() this would help.