This document explains the recordmode concept in SAP BI which describes how changes to data records are recorded during delta processing. There are three main types of delta processing - ABR (After Before and Reverse image), AIE/AIM (After Image), and ADD (Additive image). Each type supports different update methods and data loading options. The recordmode values identify the type of change in the data record, such as after-image, before-image, add, delete, new image, or reverse image.