Thank you for having successfully completed your check-In. Your information will be transferred to SEVIS within one business day, allowing U.S. government databases to know that you are now eligible to start work (ie Social Security; E-Verify).
As a reminder, unless your job offer specifies otherwise, you should follow the Department of State and the Social Security Administration guidance on waiting 10 days after check-in to submit the Social Security application (to avoid issues).