Xbox One external hard drive: contents of the drive will be deleted?

I recently bought an external hard drive for the Xbox One X and I just connected it. Now it is said that I can use the hard disk either for media, or for games and apps, but in the latter case, the drive must be formatted, which means that the entire contents of the drive will be deleted.

Now I wanted to know what exactly that means? Does that mean that my scores are gone? My pictures, my videos? Or are they simply moved to the external hard drive?

Formatting basically means erasing everything on a hard drive, making it easy to know who is scrapping or selling a PC, but the XBOX is exactly the same.

Please read this article here, because I do not have a console, I can't help anymore. The article should show what has to be considered in the XBOX, if you connect an external hard drive:

https://www.giga.de/...-beachten/

I found out, thanks.

No thing. What was it?