I have referred to many grammar books and they say that
"A cow gives us milk" and "The cow gives us milk" mean the same thing. They mean all cows give us milk or cows give us milk.
I know that the article "the" talks about the whole class.
Does the indefinite article "a" also talk about the whole class of animals in the given sentence?
I would like to know when a cow and the cow differ in meaning.