UPC_YS_API_ROW is a standard SAP Structure so does not store data like a database table does. It can be used to define the fields of other actual tables or to process "Description of Lines" Information within sap ABAP programs. This is done by declaring abap internal tables, work areas or database tables based on this Structure. These can then be used to store and process the required data appropriately. i.e. DATA: wa_UPC_YS_API_ROW TYPE UPC_YS_API_ROW.
The UPC_YS_API_ROW table consists of various fields, each holding specific information or linking keys about Description of Lines data available in SAP. These include CHANM (Characteristic), CHAVLEXT (Field for any characteristic value (external display)), TXTLG (Long Description)... 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. .