The types of fields on a webform are called "elements." There are a lot of types, and some are obvious and some are more complicated. When you add an element, the dialog that pops up provides brief descriptions of each.

A text field is pretty straight forward.

An email field does some validation, to prevent people from submitting things that are not email addresses.

Similarly, there is a RIN element that makes sure the value submitted is a valid RIN.

Otherwise, people could enter "bananas" and that wouldn't help you.

We'll talk about many of the more complicated elements later.