Is there a difference between DVD authoring and DVD ripping?
thanks.

DVD authoring is assembling the individual components (movies,
audio, menu's, subtitles) and creating a DVD structure (optionally
burning it as well).

Ripping is the word used to get the footage of a DVD video disc
to your harddisk or another DVD. Usually this involves decrypting
since the commercial DVD's are encrypted to prevent copying (which
has been cracked a long time ago) originally.

The two are their opposites.