biosdevname in its simplest form takes a kernel name name as an argument, and returns the BIOS-given name it "should" be. This is necessary on systems where the BIOS name for a given device (e.g. the label on the chassis is "Gb1") doesn't map directly and obviously to the kernel name (e.g. eth0).
These details are provided for information only. No information here is legal advice and should not be used as such.