What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
Sub users are JotForm accounts with which you have shared your forms, such that they can edit your forms and/or view all submissions of your forms.
This means that sub accounts are the people with whom you collaborate on editing your forms, or the people with whom you have shared your collected form submissions / responses. Please take a look at the guide I have linked above regarding how to set up sub accounts, and what permissions sub accounts (can) have.
People that are just completing your forms online are not your sub users, they are simply customers / users / people / folks, whichever term you prefer. :)
Let us know if you need any clarification regarding this, we will be happy to help.