Passed in the 1600s, laws aimed at distinguishing the social status of european indentured servants from that of african slaves were known as the:

They were known as the slave codes

There was a few of these laws passed and they were used to determine when and for how long and how would someone become a slave. This included things like looking at the status of a mother, or looking at the status of their religion, or anything similar, including differentiation between indentured servitude and slavery.

Because Europe had merchants who traded with the rest of the world,so even though China was more advanced they did not have the necessary resources.
For the Islamic world they concentrated on their religion more than the sciences not to say they didn’t make some important discoveries.
And also Europe had an empire