PLI Programming language interface Calling the functions implemented in c language into Verilog,but reverse not possible with PLI.so it’s for interfacing HDL and c. PLI is only for simulation purpose By reusing the c code,we can save time Some companies,may develop some part of TB in c.so it will be useful for SOC or subsystem level verification With c, we can code comb ckt’s also If we want to work with both c and HDL then our system/server should contain both compilers