Doubt about the use of royalty contracts in Rarible

[damianlluch]

Hello, I would like to ask about the use of contracts:

https://github.com/rarible/protocol-contracts/tree/master/royalties

y

https://github.com/rarible/protocol-contracts/tree/master/royalties-registry

What is the difference between the two?
In your post on medium you mention the royalties-registry contract, but I don't see that you make use of it in this repository.
Is it necessary to implement both?

thanks