Q: copied iTunes library has iCloud icon by each song

I've copied my iTunes folder from my old MacBook Pro to my new iMac and I can see all my music songs but they all have an iCloud icon by them that has a down arrow in it. If I click on it, the song is downloaded and I can play it. My question is why is it not already in my library? I copied all songs from my MacBook Pro library. I assume some kind of permission thing. Yes this new computer is authorized. I guess I can click on and download every song in my library if my thumb holds out, but will I have a copy that's inferior to the ones I imported from my old CDs?