What is "Re-Authoring" - Blu ray?

So i just bought a Blu Ray burner, DVDFab Blu Ray copy, and a bunch of blu rays. I'm currently Backing up my pacific rim 3D.

But Someone told me and i've read a few times a phrase - "Re-Authoring"
What the hell is it? do i need to do something before i burn a file to blu ray?

Also can i burn just a video files to a disc? like an .mkv or .avi file to blu ray?

Thanks.

"P.S, i want these backups to work on my PS3"