You are working in an international accounting protocol of SAP with functions and tables.

In SAP HCM Payroll for SAP S/4HANA, WPBP is both a function and a table. As a function, WPBP (Import work center and basic pay data) is used to transfer master data on the work center and basic pay for the payroll period to internal table WPBP1. The basic pay wage types are stored in the internal table IT1. If all the fields of the table WPBP are the same during the entire payroll period, this table will contain one record1. As a table, WPBP is filled by the infotypes Actions (0000), Organizational Assignment (0001), Planned Working Time (0007), Basic Pay (0008), and Cost Distribution (0027). It contains important organizational and payment-relevant data, and different partial period parameters2.

References = Understanding functions in Payroll Schemas - SAP Community, Internal Tables for Payroll - SAP Help Portal