Hi Balaji,
I hope this gives clear understanding for frontend and backend components.
Frontend server: NetWeaver 740
+ SAP_GWFND SP07
+ SAP_UI SP09
+ UIX01HCM SP03
Backend Server: ERP 6.0
+ IW_BEP SP08
+ GBHCM002 SP12
+ GBHCM003 SP10
Regards, Masa
SAP Customer Experience Group - CEG