An Exception can be handed in AX 2012 by try, catch, retry, throw whereas there is no Finally here.
Once you defined try but there is not catch handling for specified error that will be handled by system itself. but we cannot trace out the error.
In this cases AX system gives an opportunity to handle that kind of developers unspecified exceptions will be handled by
Global::error / Global::Warning /Global::Info.
With reference to this Global class we can trace-out error.