Do the modules share the same data?
In short
Yes. All RA-Core modules read and write to one database, so a record entered once is available everywhere.
A customer, supplier, item, employee or asset is created once and used by every module that needs it. A goods receipt updates stock and the supplier balance together, and the cost of a maintenance job reaches the accounts without being re-entered.
That is why reports from different departments agree, and why month-end closing becomes a matter of reviewing figures rather than collecting them.