Yes, but they should avoid staying abroad for more than 6 months, which can raise residency questions.

If they plan to be away over 1 year, they need a re-entry permit.

If they plan to be away over 1 year, they need a re-entry permit.

Yes, Green Card holders can travel abroad, but trips longer than 6 months can raise residency questions, and stays over 1 year usually require a reentry permit to avoid losing status.