passing data between forms or somehow linking them

not sure how to explain this, but if i have one form, which submits its info & then redirects the user to another form after submission, which they subsequently fill out and in turn is also submitted - is there some way to link those two form submissions together, so the recipient of the submissions can tell that both of the forms are from the same person?
like perhaps an auto generated number (order number for example) from the first form, being passed to the second form & included in that second forms submission.
make sense?