B121 is a standard SAP Table which is used to store OutputDev. data in SAP systems, such as SAP R/3, S/4HANA, depending on the version and release level.
The B121 table consists of various fields, each holding specific information or linking keys about OutputDev. data available in SAP. These include KAPPL (Application), KSCHL (Output Type), OUTPUT_DEV (Spool: Output device), KNUMH (Number of output condition record)... See below for full list along with technical details, documentation, text table, check tables, foreign key relationships, conversion routines, relevant tcodes and example ABAP select code etc. .