peekay4 is correct. once you enter on a CR1 you have Permanent Residency status - but it is conditional on you remaining married and living together etc etc and that you do not leave the US for an extended period of time (same as a 'regular'
PR). If you leave the US for an extended period, then you are deemed to have abandoned your status. You can apply for a Re-Entry Permit if you were to want t o leave the US for an extended period but you will still be required to file US tax returns from wherever you are.