What is the difference between Persian and English cucumbers?

What is the difference between Persian and English cucumbers and can I use them interchangeably in recipes?

Persian and English cucumbers can be used interchangeably in any recipe I have ever come across. They are both thin-skinned enough to be served unpeeled, and both are nearly seedless. (Persian cucumbers may have a few seeds). English cucumbers are often sold wrapped tightly in plastic and tend to be about a foot long, while Persian cucumbers are only about 5-6 inches.

The Cucumber Salad recipe pictured here is a great example of a recipe that calls for Persian cucumbers, but English cucumbers would work fine.