The difference between : I want you to and I need you to :

I want you to expressing that telling someone some one that you have a desire or would like them to do something.
I need you to expressing something that is required or wanted .
examples:
●I want you to educate me .
●I need you to study harder In school.

The difference between ' I want you to' and 'I need you to' is as follows :

'I want you to' expresses someone's desire to have you do something for the person.
'I need you to' expresses someone's strong and urgent desire to have you do something and that it is reqiured of you to do so.
examples:
●I want you to educate me .
●I need you to study harder In school.