Difference Between _n and _N in Stata

This video explaines the difference between small and capital n in stata. The small n i.e. _n is used for generating serial number of it is used for row number in stata. where as _N is used for total number of observation, we can also use both these system variables with bysort i.e. generate total number of observation for each group or generate serial number for each group. Website: thedatahall.com