Understanding SAP S/4HANA Read Snap Behaviour

I am using "SAP S/4HANA Read" snap in my project.
I am not clear from given documentation that how this snap works while fetching data from SAP.
I have following queries on it:
1. How it reads data from SAP,  It will fetch all records from SAP side in one go or it will internally make multiple calls to fetch all data from SAP ?
2. How to set and use HasNext and Next Url config in this snap ? We didn't find any documentation about it.