system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is the difference between sharing music over the internet and letting a friend borrow a cd?

Sharing music over the Internet via torrents, YouTube downloaders, etc. is illegal. Why is me sharing a few albums (that I bought) with friends of mine, assuming they'll just load it into their itunes, legal?
gpt
I state this neutrally but it is true.

Loading your CD into their iTunes is against the law.  The possessor of a CD is granted rights to use it, not copy it.  Money was paid to the label and the band for one copy of the music, that's it.  Your friend can listen to the CD, you can listen to the CD together, you can give the CD to people or even sell it to someone else, but you cannot make a copy of it.