SHARINGAN

Sharingan is the special ocular ability which gives the people having it the ability to see other peoples’ movement in slow motion and shows them the position which their opponent will attain even before they know it. Sharingan enables its wielder to see and identify the type of sign which their opponents make and copy it. Only bloodline limit Justus’ can’t be imitated through Sharingan. It also shows its wielder the nature and color of their opponents’ Chakra. No Sharingan user can be caught in normal genjutsu as Sharingan makes its wielder invincible to the normal genjutsus.
The upgraded Sharingan or Mangekyou Sharingan gives its wielder forbidden powers and makes them almost invincible. Different Mangekyou gives different power for example Itachi’s Mangekyou gave him the strongest genjutsu – Tskuyomi, a fire which never dies out – Amaterasu and the strongest defense and offence – Susano’o. Before dying Itachi gave his Mangekyou powers to Sasuke but Sasuke’s Mangekyou enables him to manipulate Amaterasu.
Kakashi’s Mangekyou, gives him the power to open up another dimension which can suck in anything be it Jutsu or any blast or article.
The final phase of sharingan is the Rinnegan 

Here's the step by step devlopment of SHARINGAN:

1.-Sharigan

2.-Sharigan version 2

3.-Sharigan version 3

4.-Mangekyo Sharigan

5.-Eternal Mangekyo Sharigan

6.-Rinnegan