Land of Water

The Land of Water is one of the Five Great Shinobi Nations and contains the hidden village of Kirigakure. It is composed of many islands, with each having its own unique traditions. The Land of Water and Kirigakure are shown only briefly in the series, but several ninja featured in the series hail from this area.
Kirigakure ("Village Hidden in Mist") is the hidden village of the Land of Water. The leader of the village is known as the Mizukage. Madara Uchiha has been referred to as the Mizukage, though it is unclear when he held the title. The ninja in Kirigakure specialize in water-based jutsu. During the rule of the Fourth Mizukage, Yagura (who was also the host for the Three-tails), Kirigakure was known as "Bloody Mist" as it used brutal methods to train its ninja, requiring prospective ninja to fight their comrades to the death. The Fifth Mizukage was first seen when the Raikage called all Kages to the Land of Iron. After Zabuza Momochi killed all the students in his class, however, the process was discontinued. The Mist, like Iwagakure and Kumogakure, has also had possession of two tailed beasts, the three tailed beast and the six tailed beast. Zabuza became part of the Seven Shinobi Swordsmen of the Mist, the strongest group of ninja in the village and signified by the unique swords they carry. Aside from Zabuza, three other members have been revealed in the series: Kisame Hoshigaki, who abandoned the village and joined the criminal organization Akatsuki, Raiga Kurosuki, who is introduced towards the end of the Naruto anime, and a boy named Chojuro who is a bodyguard for the Mizukage. Suigetsu, who joined Sasuke when he killed Orochimaru, was trained to become a member of the seven swordsmen of mist. He has mention that his brother was/is a member of the swordsmen.

Land of Lightning

The Land of Lightning is one of the Five Great Shinobi Nations and contains the hidden village of Kumogakure. It is composed of numerous mountain ranges. The country and its inhabitants go largely unseen until late in the second half of the series.
Kumogakure ("Village Hidden in the Clouds") is the hidden village of the Land of Lightning. It is located on a high mountain, literally hidden in the clouds. The leader of the village is known as the Raikage. Similar to Iwagakure and Kirigakure, Kumogakure has had two tailed beasts in its possession: the two-tailed demon cat, sealed within Yugito Nii and the eight-tailed beast, sealed within the Raikage's younger brother, Killer Bee. Both Jinchūriki were attacked by Akatsuki. Yugito was captured and killed through the extraction process, while Killer Bee managed to fool and evade capture by his Akatsuki assailants. Back in times, a leader of the Kumogakure made an alliance with Konoha. After the celebration of the alliance, the leader tried to capture Hinata Hyuga, to get the Byakugan. Hinata's father killed the leader, but the rest of the Kumogakure saw that as a break of the alliance. They wanted the corpse of Hinata's father in exchange of their leader's life, or they would start a war between Kumogakure and Konohagakure. The Hyuga clan gave Kumogakure the corpse of Neji's father, instead for Hinata's father, because the Byakugan of Neji's father was sealed when he died, so the Kumogakure didn't get any Byakugan at last.

Land of Earth

The Land of Earth is one of the Five Great Shinobi Nations and contains the village of Iwagakure ("Village Hidden Among the Rocks"). The leader is called the Tsuchikage. Not much is known of this land as it has mainly been mentioned in passing in the manga. Like Kumogakure and Kirigakure, it has been revealed that Iwagakure had two tailed beasts in its possession: the four-tailed beast, sealed within an old man named Rōshi, and the five-tailed beast, sealed within a large, armor-clad man named Han.

Land of Waves

The Land of Waves is a poor nation, and as a result does not have a hidden village. It is an isolated island, but was prosperous until the country was taken over by Gato, who monopolized the economy. The Land of Waves is introduced early in Part I, and Team 7, which consists of the main characters of the series, travels to the Land of Waves as bodyguards for a bridge builder. With the aid of the populace of the Land of Waves, Team 7 manage to defeat Gato and his hired assassin Zabuza Momochi, and his assistant Haku, and restore the country to its former status. As a sign of gratitude, the bridge is named the "Great Naruto Bridge" in honor of Naruto Uzumaki, the main character of the series.

Tailed beasts

The tailed beasts are nine giant demons that serve to drive the plot of the Naruto series. They are differentiated by the number of tails they have, with each possessing an amount from one to nine. The beasts are large, living forms of chakra, giving them power that far outmatches most ninja. However, this immense strength is tempered due to their bestial nature, which restricts them from being smart enough to use it effectively. Beasts sealed within another person are able to benefit from the knowledge of their hosts, giving them the ability to speak and better utilize their powers. Akatsuki, a criminal organization that becomes one of the primary antagonists of the series, spends much of their screentime trying to capture the first nine beasts or their hosts. Once captured, Akatsuki's members seal the beast away for future use. The Akatsuki leader Pain, claims these beasts will facilitate in the creation of a weapon capable of destroying an entire country whilst the group's true leader Madara reveals his intention of merging the tailed beasts into their original form, the ten-tailed beast.
Only some of the beasts are actually seen in the series, and those that appear are not fully explained. The second Naruto artbook, released in July of 2009, provides an explanation of the beasts and their hosts. The beasts are, in numerical order: Shukaku, the one-tailed tanuki (sealed within Gaara of Sunagakure); the two-tailed monster cat (sealed within Yugito Ni'i of Kumogakure); the three-tailed turtle (previously sealed within Yagura of Kirigakure); the four-tailed gorilla, based on the Great Ape from Dragon Ball (sealed within Rōshi of Iwagakure); the five-tailed dolphin-horse (sealed within Han of Iwagakure); the six-tailed slug (sealed within Utakata of Kirigakure); the seven-tailed beetle (sealed within Fū of Takigakure); the eight-tailed ushi-oni-like beast (sealed within Killer Bee of Kumogakure); and the nine-tailed demon fox (sealed within Naruto Uzumaki of Konohagakure). As of the latest Naruto chapter, only the eight-tailed and the nine-tailed beasts have yet to be captured by Akatsuki.

Hosts

Jinchūriki ("Power of Human Sacrifice"?, English "Spiritualist Medium"), or simply hosts, are those who have had a tailed beast sealed into their bodies. Jinchūriki are created so that ninja villages can gain control over a tailed beast, having the host harness the beast's power as a weapon of battle. In most instances, they are actually stronger than the tailed beast they contain, as they have the knowledge to effectively control the tailed beast's strength. Each of the hosts that have appeared so far within the series also possess a physical characteristic that resembles their beast; Naruto for example has fox-like whisker-marks on his face, while Gaara has tanuki-like rings around his eyes.
According to members of Akatsuki, hosts of tailed beasts are typically lonely people who loathe humanity. When Akatsuki captured their first three jinchūriki, no one from their villages cared, and in fact were thankful to be rid of them. If a beast is removed from its host's body the host will die. Similarly if the host dies with the beast still sealed within them, the beasts will die too. Because of this beasts tend to be protective of their hosts, forcibly taking action when their host is in danger (as demonstrated with Gaara's sand shield). Hosts can communicate with their beast in an effort to use the beast's powers at will. Killer Bee (host of the eight tailed beast) seems to have had the most success in doing so, having a mutual relationship with his beast and being able to fully unleash the beast within him while still maintaining his sense of self. Naruto is the opposite; he is often in conflict with the fox and when he reaches four tails or more he loses complete control of his body.

Academy ninja

The academy is where would-be ninja start; they are not actually considered ninja until they graduate. Academy students take formal and practical tests of all sorts and are taught basic ninja skills, such as martial arts, techniques, physical fitness and the way of the ninja. Basic weapon usage, such as kunai and shuriken, are commonly taught. Elementary ninja techniques, such as transformation jutsu and clone jutsu, though they vary from village to village, are also taught. Once a student has become proficient in these areas they are allowed to graduate. Upon graduation, students are organized into three-man teams under the leadership of a Jonin. In some villages, the Jonin administers a final test to determine whether or not the team will be able to advance to the rank of Genin. Those who fail must return to the academy. When Naruto Uzumaki graduates at the start of the series, only nine of the twenty-seven graduates become Genin.

Genin

Genin (literally "Lower Ninja", Viz "Junior Ninja") are the lowest level of ninja. Genin are given headbands with their village's symbol on it to represent what village they come from and that they are full fledged ninja. Genin are also put in three-man cells, and are then assigned a Jonin sensei to mentor them. This is done to teach the Genin teamwork and experience true ninja life under the supervision and protection of an elite shinobi. The make-up of these teams is based on the individual skills of the Genin, so that there will remain a balance between the teams. When they become Genin, ninja start to do their bit for their village's economy, for which they are given a small payment. They are typically sent either on D-rank missions, which are the lowest rank and are almost entirely risk-free jobs of manual labor, or experienced Genin are sent on C-rank missions, which are a cut above that and begin to verge on real "ninja" work, though they generally have a very low possibility of risk to the ninja involved.

Chunin

Chunin (literally "Middle Ninja", Viz "Chūnin" and "Journeyman Ninja") are ninja who are qualified to watch over and guide other ninja. Chunin have reached a level of maturity that primarily consists of leadership skills and tactical prowess. Some of them, like Shikamaru Nara, serve as team leaders in charge of small teams who need to make decisions and utilize the skills of the shinobi under their command to the maximum effect. Upon reaching Chunin level, ninja can wear an identifying tactical vest that holds ninjutsu scrolls. This vest is not required; instead, some look for more elaborate clothing like capes or robes. Chunin are typically sent on C or B-rank missions.
To become a Chunin, a Genin participates, with his or her team, in a large examination, known as the "Chunin Exams," hosted twice a year due to the growing number of ninjas. In the past, each village held their own Chunin exam. After the 3rd Ninja World War, allied ninja villages agreed to hold the exams together at the selected village that would host the exam, so villages could improve and strengthen their relationships. Another advantage is that ninja that took the exam might attract clients who are interested in hiring them. The exam is a test not only of strength, but information gathering abilities, survival skills, and adhering to guidelines. Those who have all of these qualities are grouped together into predetermined fights, watched by a council that decides who becomes a Chunin and who does not. While the winners are able to proceed to fight the next opponent, it is aptitude, rather than winning, that is evaluated to determine whether a candidate is promoted. This way even one who loses his or her first match can become a Chunin as evidenced by Shikamaru's promotion while he surrendered to Temari in the first round.

Jonin

Jonin (literally "Higher Ninja", Viz "Jōnin" and "Elite Ninja") are generally highly-experienced ninja with great individual skill who serve as military captains. They are often sent on A-rank missions, and experienced Jonin, like Kakashi Hatake, may even be sent on S-rank missions (which are considered to be the most difficult), and may carry out missions alone. They are sometimes assigned as sensei for three-person teams of Genin. Most Jonin are able to use two or more types of elemental chakra. Though it is as yet unknown what one has to undergo to become a Jonin, it is mentioned in the Naruto Anime Profiles that Jonin are appointed.
Tokubetsu Jonin (Tokubetsu Jōnin?, literally "Special Higher Ninja" English "Special Jonin", sometimes known as Tokujō for short) are ninja who, rather than all-around Jonin training, have Jonin-level ability in a single area or skill, much like warrant officers of real-world militaries (e.g. Ibiki, who specializes in interrogation). They are elite specialists in their areas and are often assigned as subordinates to regular Jonin when their services are needed. They sometimes are seen as lower ranked than Jonin because they are good or the best in one field and they lack talent, or even ability in others.

Kage

Those who have achieved the title of Kage (literally "Shadow") are the leaders of the five most powerful Hidden Villages and generally (but not exclusively) the most powerful ninja in their respective villages. These villages do not rule the country, but are equal to the government. The Kage stand equally with the rulers of their countries, oversee the activities of their villages, and are the leaders of ninja society. There may be exceptions, however, as a ninja may be the most powerful at the time of being installed as Kage, but may become less powerful upon aging, eventually being surpassed by a younger ninja. A Kage may retire and give the title to someone else; however, once granted, the title is held permanently, creating a situation where a village has two Kage at the same time, with only one of them actually active. Their elite status is also attributed to the tendency for most Kage to have family members who were previous Kage, or be personally taught by a former Kage or student of a former Kage, or some combination of these factors. The five Kage have different titles depending on their country. Those titles are:
Hokage (literally "Fire Shadow") Kage of Konohagakure.
Kazekage (literally "Wind Shadow") Kage of Sunagakure.
Mizukage (literally "Water Shadow") Kage of Kirigakure.
Raikage (literally "Lightning Shadow") Kage of Kumogakure.
Tsuchikage (literally "Earth Shadow") Kage of Iwagakure.
The anime introduced a sixth Kage, the Hoshikage (literally "Star Shadow"?) from Hoshigakure (Village Hidden in the Stars). However, this was a self-given title and not officially recognized by the five other villages.

The ANBU

The ANBU is actually short for Ansatsu Senjutsu Tokushu Butai (literally Special Assassination and Tactical Squad), and is an organization of assassination squads that serves directly under the village's leader. The ANBU wear porcelain animal masks in order to distinguish themselves from normal shinobi and to conceal their identities, and also have standard uniforms consisting of black and gray armor, arm guards, a signature spiral tattoo on their shoulder(Men: left shoulder. Women: right shoulder) a Ninjatō strapped on their back. They know the layout of the human body in detail, and have developed several techniques to perform their duties, such as paralyzing the target. ANBU are considered the elite, and they perform high-ranked and dangerous missions. Within the ANBU of Kirigakure,and presumably other ninja villages there exists a sub-group called Hunter-nin (literally "Chasing Ninja", English TV "Tracker Ninja"), given the specific duty of hunting down rogue ninja, and destroying their bodies, so their village's secrets won't be revealed to foreign ninjaKonoha is shown having two ANBU-like organizations, though are separate from ANBU entirely. The Konoha Military Police Force, or Military Police for short, is a unique organization in Konoha, though other villages may have similar organizations. Their symbol is the Uchiha crest because the Uchiha family founded the organization as a sign of trust with the Second Hokage. The Military Police previously consisted of mostly Uchiha clan members, though now that Itachi has eliminated all but Sasuke this is no longer the case. The Military Police are in charge of law enforcement within the village, and their jurisdiction is virtually unlimited except in matters that are under the Hokage's direct control. The Nijū Shōtai is a task force created by Tsunade, the Fifth Hokage, for the purpose of tracking down, attempting to capture, and, if necessary, eliminating Akatsuki members in the Fire Country. This force consists of twenty four-man teams, making eighty shinobi in all.
Konoha ANBU are usually under the direct command of the Hokage, but several years before the start of the series there was an ANBU Training Department known as the "Foundation". The Foundation was created and directly controlled by Danzo, who trained and conditioned children intensively from a very young age. This was done to completely eliminate emotions and enable its members to complete missions without being held back. The Foundation tends to go further in its belief that ninja must not show any emotion than most other ninja groups do, as they forbid any members to possess anything that may invoke emotion. It was implied that the department might have used methods similar to Kirigakure's graduation exam, including putting students against each other in fights to the death. Because Danzo is a war hawk and opposed the Third Hokage, the Foundation was disbanded. However, many former members are still loyal to the Foundation.

Medical ninja

Medical-nin are ninja who specialize in medical treatment and use medical-oriented jutsu to heal others. Examples include Tsunade and Sakura Haruno and Ino Yamanaka. Becoming a medic-nin requires excellent chakra control, because medic-nin use chakra to heal injuries. Aside from their medical training, their combat training consists mainly of taijutsu skills, with emphasis placed on evading enemy attacks, as the death of the medic-nin could result in the death of the team, though medical techniques can also be used offensively. On dangerous missions, a medic-nin will usually be sent along with the team, to increase the survival rate of that team.

Rogue Ninja

Rogue Ninja are ninja who have abandoned their Hidden Village, and as such can include ninja of every rank. These ninja are considered traitors and are hunted down because of the secrets they may hold. Other Hidden Villages would be interested in purchasing this information because it could be useful in gaining an upper hand in battle or obtaining a bloodline limit unique to a village. Some villages (Kirigakure being the only known example) create special units of hunter-nin to take care of this problem, although it's unlikely that every missing-nin has a team of hunter-nin sent after them.