From the Cloud Foundry Documentation:

memory Use the memory attribute to specify the memory limit for all instances of an app. This attribute requires a unit of measurement: M, MB, G, or GB, in upper case or lower case.

Can someone define the difference between M vs MB and G vs GB?

Initially I thought M is just MB and G is just GB. But my issue in Predix was resolved when I used MB instead of M. I wish to understand the significance