What is a certificate of apprenticeship?

A friend of mine is working on her Associate in Arts in both Business Management and Marketing and she told me that she’s also getting a “certificate of apprenticeship”.

I wasn’t quite sure what that meant, so I tried to look it up. I found that there are apprenticeship programs in trade fields like welding or electrical work. As a result, these workers become more skilled at their jobs and can demand higher pay.

I also read about a professional apprenticeship in engineering for people who graduated with their bachelors, worked in the field for about four years, and then go back for the certificate in order to make a higher salary and, again, become more skilled.

She doesn’t even have her associates yet, and she’s going for business/marketing. How would this even work? And if you are familiar with this, what kind of value is in it for her future job search?