Each village has a standard of how Chuunins and Jounins are distinguished, but as a whole, Leaf Village is pretty lenient on how exactly one should be dressed. Chuunins and above wear a dark green vest/jacket that goes down to the waist, and you
could either zip it closed, or just let it loose like Maito Gai.

There are some exceptions. Yuuhi Kurenai seems to be covered in a white garment of some kind, and Anko has a fishnet undershirt and a beige trenchcoat. But for the majority, the dark green flak jacket with a swirl on their back signifies that they are from Konoha.

Hidden Cloud ninjas have a thicker jacket than Hidden Leaf ninjas. It appears to be made of a hard, plastic covering, and a thick inside. This may be due to Hidden Cloud being located far north, where it undoubtedly is very cold and wet. They also have a dark sash strung around their waist, and presumably thick as well pants.

Hidden Mist ninjas, being from a poor country, have a simple velcro vest. Momochi Zabuza once wore this, and at a glance, it holds nothing on the outside, but it is of a very tough metal, which sharp objects have a most difficult time penetrating.

Hidden Sand Chuunins and (presumably) Jounins, don't have velcro or buttons to close their vest/jacket. Rather, it seems to be a sort of armor in which the wearer must pull over their heads to wear, and they have shoulder guards to prevent slashes to the arm. They also have six scroll pouches on the front of the vest.