Hi, Go through SAP-HR. SAP-HR is with the basic modules of PA,OM,Time Payroll. SAP HR is a SAP module developed and customized by ABAP codes that deal
with employee records.SAP HR is a completely SAP module where as SAP HCM is a Business Suite. SAP HR can be developed and customized by ABAP Codes where HCM can be developed by web based tool.