Thanks to Denth for several edits.

Since the dawn of Jedi history, seven fighting disciplines have arisen, known as the Seven Forms. The Forms represent differing styles and philosophies of combat. Each Form has its respective merits. Naturally, Jedi do not train in just one Form; they must mix styles from different Forms to achive fighting skill.

Form I
Form II
Form III
Form IV
Form V
Form VI
Form VII

Form I

Form I is based on ancient sword-fighting traditions, since the principles of blade combat have remained much the same. The basics of attack, parry, body target zones, and the practice drills called cadances are all here. This is similar to standard sword combat taught as the basics of almost every style of sword combat.

Form II

The ultimate refinement of weapon-to-weapon combat became Form II, advancing the precision of blade manipulation to its finest possible degree and producing the greatest dueling masters the world has ever seen.

Form III

The third discipline focuses on deflection and defense alone. It is a highly refined expression of non-aggressive Jedi philosophy. Form III maximizes defensive protection in a style characterized by tight, efficient movements that expose minimal target area compared to the relatively open style of some of the other forms.

Form III Masters are considered invincible.

Form IV

Form IV is the most acrobatic Form, heavily emphasizing Jedi abilities to run, jump, and spin in phenomenal ways by using the Force. Masters of Form IV incorporate all the ways in which the Force can help them go beyond what is normally possible for a person to do. Their combat is astonishing to watch, filled with elaborate moves in the center of which a Jedi may be all but a blur.

Form V

Form V arose to address a need for greater power among the Jedi. Jedi who feel that Form III could be too passive and Form IV too open and not using enough power in the attack, train in Form V, which is a mix of these two Forms. A Form III master might be undefeatable, but neither could he necessarily overcome his enemy. Form V focuses on strength and attack moves. A dedication to the power and strength necessary to defeat an enemy characterizes the philosophy of Form V, which some Jedi describe by the maxim "peace through superior firepower." To some Jedi Knights, Form V represents a worthy discipline prepared for any threat; to others, Form V seems to foster an inappropriate focus on dominating others.

Form VI

This Form balances the emphases of other forms with overall moderation, in keeping with the Jedi quest to achieve true harmony and justice without resorting to the rule of power. It is considered the "Diplomat's Form" becuase it is less intensive in its demands than other disciplines, allowing Jedi to spend more time developing their skills in perception, poltical strategy, and negotiation. In practice, Form VI is a combination of Forms I, III, IV, V. Young Jedi spend their first few years studying Form I and then a year or two with each additional Form before completing their training. By comparasion, a Master of any other Form will spend at least ten years studying only that form after completing the basic Form I training. Form VI well suits the modern-day Jedi's role in society, in which a Knight overly trained in martial combat might be at a loss to resolve a complex political conflict between others, however, full Masters of other Forms sometimes consider Form VI to be insufficently demanding.

Form VII

Form VII was created by Mace Windu. It is also known as Vaapad, named after a beast who movements are so fast that when one attacks, you can't see its clutches. Only high-level masters of multiple Forms can achieve and control the ultimate discipline known as Form VII. This is the most difficult and demanding of all the Forms, but it can eventually lead to fantastic power and skill. Only Mace Windu and his Padawans have been known to use Form VII. Form VII employs bold, direct movements, more open and kinetic then Form V but not so elaborate in appearance as Form IV. In addition to very advanced Force-assisted jumps and movements, Form VII tactics overwhelm opponents with seemingly unconnected staccato sequences, making this Form highly unpredictable in battle. This trait makes for a much more difficult execution than the graceful, linked move sequences of Form IV. Form VII requires the intensity of Form V, but much greater energy since that focus is wielded more broadly. Form VII draws upon a deeper well of emotion then even Form V, yet masters it more fully. The outward bearing of a Form VII practitioner is one of calm, but the inner pressure verges on explosion. Form VII is still under development since so few can achieve the necessary mastery to advance the art. When using this Form, it can be extremely difficult to control one's emotions, as Vaapad is very similar to the form the the Sith use. In fact, only Mace Windu has been able to control himself. Because of these dangers, it is not recommended that Jedi use this Form.