E-Rank jutsu are the general skills every ninja learns at the Ninja Academy. The students are expected to know these skills before graduating to Genin.
Examples: Bunshin no Jutsu, Kawarimi no Jutsu, Henge no Jutsu
D-Rank jutsu are Genin-level techniques. These skills will make up most of a Genin's arsenal.
Examples: Kage Shuriken no Jutsu, Juujin Bunshin, Shunshin no Jutsu, Narakumi no Jutsu
C-Rank jutsu are Chuunin-level techniques. Some Genin will have one to two skills at this level, serving as their "trump cards" to pass the Chuunin Exams.
Examples: Kuchiyose no Jutsu, Nikudan Sensha, Shintenshin no Jutsu, Shishi Rendan
B-Rank jutsu are Jounin-level techniques. Chuunin and Special Jounin are able to utilize most jutsu at this level.
Examples: Kage Bunshin no Jutsu, Omote Renge, Sensatsu Suishou
A-Rank jutsu are Jounin-level and forbidden techniques. Some Jounin will develop their own unique jutsu from this level to serve as their "trump card" but these are mainly known to Kage-level ninja.
Examples: Chidori, Tajuu Kage Bunshin no Jutsu, Juin Jutsu, Gogyou Kaiin,Rasengan
S-Rank jutsu are the generally forbidden or secret techniques known only to one ninja.
Examples: Edo Tensei, Raikiri