A Joiner in Australia is someone who works in workshop, bench joinery, making doors, windows, cabinets, set up, use and maintain static workshop machines.
A Carpenter in Australia does 1st fix 2nd fix, roof trusses, more onsite work then a Joiner. If you do both of these tasks and float between what Australia deem as a Joiner and a Carpenter you could complete the Carpenter and Joiner skills assessment.
I would check our free Australian points visa calculator or speak to one of our skilled team as the skills assessment gained will determine what occupation you come under when you apply for an Australian skilled visa.