One of two methods of using the Force, the light side was aligned with calmness, peace, and passiveness, and was used mainly for knowledge and defense. The Jedi were notable practitioners of the light, being selfless servants of the will of the Force,and their enemies, the Sith followed the dark side of the Force.
The light side of the Force was primarily used for defensive abilities as opposed to aggressive ones. According to Yoda, the dark side was not more powerful than the light side in and of itself, but was merely "quicker, easier, more seductive." Of course, by no means were the followers of light unable to wield the light as a tool for battle.
However, practitioners of the light side possessed abilities that users of the dark side often lacked. Light side practitioners were able to "heal" a bled kyber crystal, which were reddened by dark side users, restoring them to a pure form. An adherent of the light side could also master the ability of becoming a Force spirit, which allowed the user to preserve their consciousness after death and manifest as a spirit to commune with the living, without the need of a relic binding them to they physical world. With this power, some Force spirits were capable of demonstrating extraordinary feats such as calling down lightning and interacting with the mortal world.
The dark side of the Force was regarded as the dark side of the Unity by the Sorcerers of Tund,and called the shadow by the Knights of Ren, was one of two ways of channeling the Force. To tap into the power of the dark side was to indulge in raw emotions such as passion, anger, vengeance, and hatred. The dark side was greed, the fear of change, and the inability to let go. By holding on to things, one became angry and hateful, which in turn led to suffering. Those who were unable to conquer their dark side were devoured by it. The Sith were Force-sensitives well known for serving the will of the dark side and being the mortal enemies of the Jedi, who served the will of the light side of the Force.
The dark side was associated with the night. As with the light side, it was an integral part of all living things, and as the shadow of the soul, the dark side had to be continually overcome by sentients to walk the path of the light; indulging in the dark side led to imbalance. The dark side was not more powerful than the light side; it was an easier, albeit destructive, path.
Relying on anger, fear, hatred, and bitterness, the dark side of the Force granted certain abilities that wielders of the light side had no access to, such as possession and the ability to manipulate Force visions.To use the dark side was to let anger and hatred for someone wash them away entirely, allowing the individual to be filled with anger and hate and the desire to cause pain, suffering,[38] and to dominate others. Dark side abilities were considered by some to be "unnatural."