It appears there is a typo or confusion in the question, as both job titles are identical. Assuming the comparison is between 4Am 12Pm and 4Am 12Pm, there is no difference. If intended to compare with a similar role like 4Am to 12Pm shift workers, both roles typically involve working during early morning to midday hours, requiring similar certifications and work environments. The main difference may lie in specific employer policies or shift details, but generally, these roles are the same in terms of credentials and industry usage.