There are no genuine parts that you can buy new from third parties. And apple seems pretty clear with their software locks that salvaged parts are also not authorized. So, I believe authorized parts are the ones that come in your device from the factory, and ones they sell to you first party.
There are no genuine parts that you can buy new from third parties. And apple seems pretty clear with their software locks that salvaged parts are also not authorized. So, I believe authorized parts are the ones that come in your device from the factory, and ones they sell to you first party.