Despite what many people think, there are actually quite a few differences between cucumbers and zucchini, such as the fact that the flowers on cucumbers can not be eaten while the flowers that grown on zucchini plants are very much edible. Cucumbers are classified as fruits whereas zucchinis are classified as vegetables.
Essentially this means that the two foods are prepared differently and are therefore in a completely different classification. You will find that the way in which cucumbers and zucchini are cooked is also very different. While zucchini becomes very sweet and brown when it is cooked, cucumbers are typically cooked on top of the stove and have much more of a crunch to them. Overall there are actually quite a few differences between cucumbers and zucchini.