From unconditioned stimulus to conditioned response

Therefore, Classical Conditioning consists in associate an unconditioned stimulus with a conditioned response.
The unconditioned stimulus produces an unconditioned response or reflex, which is automatic. By adding a neutral stimulus, that is to say, a stimulus that at the beginning does not produce any special response but as it is presented always along with the unconditioned stimulus, after a while it is associated with the unconditioned stimulus. Consequently, a conditioned response will be produced.
Hence, the response is conditioned because it is caused by a neutral stimulus, and the unconditioned stimulus does not need to be introduced any longer to produce that response.