What is the difference between `GvNAME` and `GvENAME`?

Question

In perl sources GvNAME and GvENAME. Both return name for given gv. But second stands for effective name.

Dumping names I have not seen the difference.

May someone clear what is the difference and provide example which shows it?

UPD
Because this is related to naming too. What is difference between HvNAME vs HvNAME_HEK

Answer 1

The "effective" means who create this gv.

For example your module Module:: define my_sub. Then this sub was imported into Main::. So the sub name is Main::my_sub but effective name is Module::my_sub