how to load master data and transaction data at a time with thw help of flat file or R3 system in SAP BW system??

hi

i am very new to SAP BI.I have created a flat file in which i have give some field as attribute and some field as non attribute now i have two question in my mind:

1> How to find out which is master data??

2>How to find out which is transaction data ??

i know the defnitions of masterdata and transaction data but practically i am confused and one more doubt as wheather master data and transaction data can be loaded at a time??

thanks