A RESIDENT in your LOAD statement defines the source of the input table, i.e. it defines that the table should be loaded from your data model, using a table already loaded in your script in a LOAD statement before your current LOAD.
An incremental LOAD is a strategy to not load all data from the (DB) source, but only e.g. changed / inserted data and get the "old" data from a e.g. a QVD file.
See the examples in the reference manual, or search the forum for both expressions ("RESIDENT LOAD" vs. "INCREMENTAL LOAD"). You should find a lot of samples, e.g.
