SKU
This refers to the product used on the shelf. Meaning that any product on the shelf needs to have a number and counted as a SKU, even if we have the same product but with different versions of the same product and/or concept, then we will always have a SKU for this version.
SRP / MRP
Shelf Ready Packaging, is basically the box / container that the products are transported in and is used as part of the branding on the shelf.