Apprentice
At around 12 a boy became and apprentice. He lived with a master craftsman, slept in the workshop and received no pay.
Journeyman
He became a journeyman after 7 years. He could be paid for his work and could travel to different workshops and towns for work and experienced.
Master Craftsman
He applied to become a master craftsman. He created a masterpiece. If the guild decided it was good enough, he was accepted and could open his own workshop.