What's the difference between an SAP system and a non-SAP system?

SAP administers ERP software which integrates various business processes and functional areas including: manufacturing, sales, inventory control, finance and human resources. SAP software is based on these functional areas; companies can choose to purchase just a few modules or all of them.

Any computer which has SAP software installed on it is called an SAP system. Computers which don't have SAP software are non-SAP systems. It is normal for any medium size company to have 10-15 SAP systems. This figure varies depending on the size of the company and what modules they have purchased.