At each successive level (Initiate - Apprentice- Knight - Master - Council Member - Grand Master) a Jedi may learn one of the seven forms of the Old Jedi Order, or one of the three forms of the New Jedi Order if a current or former member, and a weapon-specific or other form. The same rules and concepts apply to the Sith and their equivalents.

The Seven Forms of the Old Jedi Order
Form I Shii-Cho "The Way of the Sarlacc"
The Determination Form

The original lightsaber form, Shii-Cho is the basic foundation upon which all other lightsaber forms are built. Thusly, any Force organization that utilizes lightsaber weaponry teaches this form to its new members. Based largely on the principles of sword-fighting, it is a simplistic form, encouraging deliberate tactics and calling for continuous, step-by-step advancement through wide, sweeping motions. It is ideally suited for multiple adversaries.

Form II Makashi"The Way of the Ysalamiri"
The Contention Form

Developed during the Second Great Schism, Makashi is an improvement of Shii-Cho, relying on precise swordplay and focusing on protecting one's weapon. Requiring fluid movements of both weapon and body, timing, accuracy, and skill are the traits necessary for development. Makashi users rely on blade manipulation, and as such, many have taken to using a curved-hilt lightsaber, but some have been known to prefer the rare Lightfoil; both of which are often ornate in nature. A Makashi practitioner is often elegant, precise, calm, and confident; often carrying an arrogant nature and seemingly dance during a duel. It is ideally suited for a single, lightsaber-wielding opponent.

Form III Soresu"The Way of the Mynock"
The Resilience Form

Developed to counter blaster-wielding opponents, it is a form of defense; tight moves, subtle dodges, and short sweeps define the form. Many users can fight for hours, if not more, as the form utilizes as little of energy as possible due to all of the movements of Soresu staying close to the body. Training stresses quick reflexes and faction positional transitions. It is ideally suited for a blaster-wielding opponent.

Form IV Ataru"The Way of the Hawk-Bat"
The Aggression Form

An aggressive form, Ataru users are always on the attack, using wide, fast, and powerful swings, constantly using the Force to aid their attacks and movements. Many are known to overcome physical limitations due to the high use of the Force, and even surpass physical performance not otherwise possible, but this comes with the drawback of not being able to utilize many Force powers during lightsaber combat. Ataru users focus on the application and smooth transition between the three axis of rotation in space. It is ideally suited for a single opponent.

Form V Shien"The Way of the Krayt Dragon"
The Perseverance Form

The Shien form was created by Soresu masters who desired a more offensive style, combining Soresu with Makashi. It requires more physical strength than Soresu or Makashi, and is distinguished by many of its practitioners utilizing a reverse grip. It is ideally suited for multiple blaster-wielding opponents.

Form V Djem So
A divergence from Shien, Djem So is founded on the same principles and concepts as its counterpart, but focused more on its application in lightsaber combat. It demands even more strength than Shien, leading to many of its practitioners being among the most physically strongest lightsaber wielders in the galaxy. It is ideally suited for multiple lightsaber-wielding opponents.

Form VI Niman"The Way of the Rancor"
The Moderation Form

Actually a form seen in use by the Legions of Lettow during the First Great Schism, Niman was eventually adopted by the Jedi, and refined into the form known today. It is, in essence, a hybrid form, in that it combines Shii-Cho, Makashi, Soresu, Ataru, Shien, and Djem So into one form. The "jack-of-all-trades" form, it spreads the strengths of all the forms, while having little weakness in it. Through this it is also the least draining of the forms and requires the least amount of training, relying on intuition, improvisation, and creativity.

Form VII Juyo"The Way of the Vornskr"
The Ferocity Form

The most vicious of lightsaber combat, it is the most difficult and demanding of all in lightsaber combat. Juyo practitioners can "eviscerate a lone enemy", in the words of Master Vrook Lamar, and utilize a chaotic and erratic style that heavily focuses on offense. Juyo utilizes bold and direct motions which are open and kinetic, but not as elaborate as those of Ataru; utilizing unconnected staccato sequences. It is strengthened by its unpredictability, and taps heavily into a users focus and emotions. It is a controversial form among the Jedi for its use of emotion in combat, and some consider its use a violation of the Jedi Code.