"The Sharingan is a one of the three great dojutusu kekkei genkai, which appears in some members of the Uchiha clan under the right circumstances.It first manifested, alongside the Byakugan, by the earliest known ancestor of the Uchiha: Kaguya Ōtsutsuki.The first of the Sharingan's powers is being able to see chakra flow. The Sharingan gives color to chakra, allowing the user to differentiate them.They are also able to tell if a person is under a genjutsu because the person's chakra flow would be irregular. The Sharingan's second-most prominent ability grants the user an incredible clarity of perception, allowing them to easily recognise genjutsu and different forms of chakra.The Sharingan's third and most well-known ability is that it grants the user the ability to copy almost any technique that he or she witnesses, apart from other kekkei genkai techniques. The user can memorise ninjutsu, genjutsu, and taijutsu with near-perfect accuracy.
Through rigorous training and usage the Sharingan matures and as such the abilities begin to develop as well. For example,with one tomoe the user can copy taijustu,with two the user can predict their opponents movements and copy techniques,when a Sharingan is fully mature it becomes three tomoe and gives the user the ability to completely use the Sharingan's abilities. The final stage of the Sharingan is the Mangekyō that is awakened through the trauma experienced from the death of a person very close to the Sharingan user. "