What does the USCIS Response mean "reaffirming the approval of this case "

I interviewed on 24th April and my cases was sent back to review. Today I got the update as under :
“we mailed a notice to you reaffirming the approval of this case and
returned the case to the Department of State for visa processing. For more information,
please contact them directly.”
Can anyone, please guide whats next and what are the chances of my Visa Approval? What this response actually mean??
Thanx