Uchiha Sasuke is a member of the famous and powerful Uchiha clan, bearers of the Sharingan. As the sole survivor of the clan's assassination by his older brother, Uchiha Itachi, vengeance is his primary and only goal - it's his fuel and life purpose for he is an avenger.
He is teamed up with Naruto, his frenemy with whom he will become best friend, and Sakura, the girl who's in love with him. He will then live through many tests and missions in Team 7, always looking to get stronger so he can meet Itachi and kill him. One day, he betrays his friends and village and decides to go and follow Orochimaru for this purpose, turning his back on everyone and thus provoking a chase between Naruto and him to make Sasuke come back to Konoha...
Uchiha Sasuke is an arrogant, vengeance-oriented, calm, and a loner, even though he is a great team player. He is devoured by his need for vengeance, which clouds his mind and heart and will affect all of his decisions and relationships.
Sasuke has jet black hair in spikes behind his head, with two big bangs on the side and two smaller ones on the forehead. That changes in Shippuden where he has many smaller bangs to accompany the two big ones. In season one he mostly wears a round-necked blue shirt with white shinobi shorts, whereas in Shippuden he wears a white kimono with a purple tied rope to keep it in place and black 3/4 pants.
He used to be drawn from season 1 to half of Shippuden in a shonen nekketsu, lively style which reminded of occidental cartoons and drawings for a younger audience, with resemblances to One Piece and Fairy Tail. It drastically changed afterwards where he grew up and the style became more traditional, even realistic, and more serious.