Some of the new terminologies used in Oracle Applications Release 12 are:

11i Vs. 12

Sets of Books = Ledgers
Global Accounting Engine = Subledger Accounting
AX Posting Sets of Books = Secondary Ledgers
Global Intercompany System = Advanced Global Intercompany System
GL Intercompany Accounts = Intracompany Balancing
Translated Currency = Balance level RCs
Multiple Reporting Currencies = Reporting Currencies
MRC Primary Set of Books = Primary Ledger
MRC Reporting Set of Books = Reporting Currency
Thin MRC Reporting Book = Journal level RC
Full MRC Reporting Book = Subledger level RC
Translated Balance = Balance Level RC

Hope it will be helpful. ………..