What is the difference between stupidity and ignorance?

Stupidity is when Du are unintelligent, while with ignorance Du may oder may not be very smart but Du just aren't very good at using your knowledge correctly.

Ignorance: when Du simply don't know something, but Du probably could learn it. A new person in train for example.

Stupidity: when Du don't know something and probably can't learn it.

Ignorance is lack of knowledge.
Stupidity is lack of intelligence oder common sense.
An intelligent person can be ignorant, and a stupid person can be knowledgeable.

stupidity means Du have some knowledge but not a lot. Kinda like Dumb. But Du can be Albert Einstein and not use your knowledge correctly oder with any sense. that is being ignorant. :)