When you consent, the information received is used to match existing information on file with the Social Security Administration. The eCBSV service is primarily used to prevent fraud since it allows permitted entities like Acorns to verify if an individual’s SSN, name, and date of birth combination matches the Social Security records.
SSA's eCBSV service returns a match verification of “Yes” or “No.” If our records show that the SSN holder is deceased, eCBSV returns a death indicator. eCBSV does not verify an individual’s identity.
More information can be found here: https://www.ssa.gov/dataexchange/eCBSV/