Either is used when one wishes to discuss one or the other.Originally Posted by johnny_bdn
Neither is used when one wishes to discuss not one and not the other.
Neither is a negated either. I doubt there is any instance in which both would be correct, but one can turn "neither" into "either" by negating the verb.
I would like either the blue suit or the gray suit.
I would like neither the orange suit nor the purple suit.
I would not like either the orange suit or the purple suit.