ERP is “enterprise resource planning”. ERP is a software , which is developed for all departments for an organisation(like sales,finance,hr,material management,production planning etc.).
In earlier days, for finance , one software, & for sales another software, like due to this integrations of all softwares is much difficult.
But right now, ERP COMES INTO EXISTANCE. WHICH IS HAVING ALL DEPARTMENTS THAT IS FOR THE GLOBAL WISE INDUSTRIES.
Then SAP is a vendor which is providing the ERP package, like as ORACLE., WHERE as SAP CLICKED THAN THE ORACLE.(in my opinion)
For SAP , Programming Language is ABAP(which is developed by SAP ),the basic books provided by sap press itself. and u can learn it by internet urself, its not a big problem.
have a nice day