A Sherwani is a very elegant dress for the men and mostly worn during wedding ceremonies these days. It is one of the most traditional Indian coat like garment worn by men, fitted close to the body, of knee-length or longer and opening in front with button-fastenings. A lot of variations to the same are available with the changing trends.
An Indo western is very close to a sherwani. The major difference lies in the way both the outfits are worn. A sherwani is very traditional and is worn with a Kurta and a Pajama, whereas an Indo Western is more modern and is worn with pants. The Indo-Western is also shorter in length as compared to a sherwani.