Upper level vs. Lower level credit

[The_Professor]

Okay, kind of a basic question in which I remain somewhat unclear about… What is the real difference/significance of upper level vs. lower level credit from an overall credit accumulation perspective? The reason I ask is that when I apply to have my various IT and professional certifications reviewed for transfer credit, depending on the institution, I am sometimes told that certain certs qualify for lower level credit but not upper. Not sure how the distinction really matters all that much, as a credit is a credit is a credit in pursuit of the grand total of 120 credits in the typical undergrad program. Any enlightenment in this regard would be greatly appreciated. Thank you…