Jounin

Jounin (上忍, Jōnin; Literally meaning "High Ninja") are generally highly-experienced shinobi with great individual skill who serve as military captains. They are often sent on A-Rank missions, and experienced Jounin may even be sent on S-Class missions (which are considered to be the greatest difficulty). It is not unusual for Jounin to go on missions alone. Jounin are generally able to use at least two types of elemental chakra, some genjutsu, and above-average taijutsu skills.

It is said that to become a Jounin one must prove worth to their village through missions as well as a test of some kind. When a ninja becomes a Jounin, he/she may be assigned three Genin to look over. One part of their duties is to help instruct and train these Genin to become competent ninja.