What is the difference between stupidity and ignorance?

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

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

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

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

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