Maintaining log in ax 2012

can anyone explain how to maintain logs in ax 2012???

i am using 4 different tables for my project.so whenever user changes any of the fields from that 4 tables, system should automatically record the changes… all the changes made so far must be recorded by the system…pls help me out for the above scenario…

You can use database log in AX. See Configure and manage database logging [AX 2012].