Hi, we usually refer as initial load to the load of all historical data, ie all data since 01/01/2018 to 29/01/2021. And the incremental load are the next loads that only adds new data, it is: add data from 30/01/2021 to the previously loaded data, this help to reduce load times and free resources to the source data.
Usually qvds are used to do incremental loads, depending of the data we use case 2,3 or 4 of this link: https://help.qlik.com/en-US/qlikview/April2020/Subsystems/Client/Content/QV_QlikView/QVD_Incremental...
