USB audio interface?

[StuBeeDoo]

I'm a 60-y-o technophobe, so please be gentle with me.

Several of the F25 ads I've seen on the 'net have mentioned "USB audio interface".  What sort of device would I need to use this?  I know that the single-disc player will play MP3 files, but TBH I've been spoiled by my E46's 6-disc MP3 changer.  I only have to rake around in the boot to change discs 4 or 5 times a year.

I have managed (eventually, it took ages to get my head around it) to get all my music collection saved on a USB external hard drive.  Would this work with the F25's USB interface?

TIA
Stuart

[X5Sport]

Highly likely that it will but the port won’t provide enough power to run a real ‘spinning rust’ type hard disk.  USB memory stick should be OK.