There is no difference it will be same

If it is in the Vugen, no diffrence, if it is in the
Controller, then it will behave diffrent based on the
iterations and duration provided.

Script behaviour will be different in case you run more 
than 1 iteration. When you specify more than 1 iteration in 
your runtime settings, only the action part will re-
iterate, and not your init and end section.

In performance testing we will try to mimic the production 
environment. Where one user will login only once and do his 
needed transactions which you mentioned here as body for n 
number of time and finally logoff and move away. To acheive 
this loadrunner Vugen has provided V-init,Action and V-end 
functions which has been controlled programatically such 
that VInit progresses only one i.e first step and V-end at 
the last in between Action iterates for the n number of 
time the tester provides to run. 
Hope this helps