Zucchini and cucumbers have a different taste and texture to them.
Cucumbers are more juicy, crisp and better tasting while zucchini has a more bitter taste to it and less juicy.
Cumbers taste good even when raw but Zucchinis only taste good when cooked or added with some other dish.
Both Zucchini and Cucumbers are members of the same gourd family but there taste is entirely different from each other.