Interface and Virtual interface

In driver or monitor ,we will get reference of interface and will store in the local interface handle,My question is what if we don’t mention it as virtual,it will also work right its just like two references pointing to same object.How virtual keyword is helpful

Chapter 25 of the IEEE SystemVerilog LRM discusses interfaces and how virtual interface handles are used. You should read this chapter as it explains the difference between interface instances and virtual interface handles.