Before revision: The difference between a street elbow and a regular elbow is the nature of the connections on either end .
After revision: and how the pipes rub against eachother as to not cause premature faults in the plumming system as to not let your male pipe pour out into the female connection allowing a leaky pipe head spurting all over a wet surface which may or may not be curved and contain a hole for the milky white coloured hole to pour into until the he gets tight and may be clogged where then you'd have to stick your fist in there several times until it spurts out againThe difference between a street elbow and a regular elbow is the nature of the connections on either end .