Mission rating question

[Kizara]

Can someone please explain it to me ? the mission ratings, I can understand I know rank D is a low level mission but what about the rest?

 

[Cruciatus]

S-rank: ultra dangerous
A-rank: Pretty dang dangerous
B-rank: dangerous, but you can handle it
C-rank: You're still kind of a noob

Edit:​

S-rank: incredibly dangerous missions. Require elite jounin level ninjas.
A-rank: also very dangerous, will always be captained by a jounin, could probably have team members that are very advanced chunin.
B-rank: could be handled by chunin.
C-rank: given to genin to keep them amused.

that's the best way I can explain it.

 

[BenjerminGaye]

Iruka talked about it before naruto went to the land of waves. So check the early chapters for info.

 

[Kizara]

Thank you I understand it now