What is meant by denatured alcohol? What is the need to denature alcohol?

What is meant by denatured alcohol? What is the need to denature alcohol?

Answer:

Denatured alcohol is ethyl alcohol which has been made unfit for drinking purposes by adding poisonous substances like methanol, pyridine, copper sulphate, etc.
Ethanol is an important chemical. It is supplied at concessional rates to industries. It is therefore, made unfit for drinking purposes to prevent its misuse.