[X-Newbies] DVDs

[peter]

	I'm in a store buying a box of DVDs to do a backup.  The guy ahead of 
me in line says, "Are you going to use those on a Mac?  They don't 
work."

	[I'm thinking: How does he know I'm going to use them on a Mac?  Do I 
LOOK like a Mac person?  What does a Mac person look like?]

	According to him, the ones that say "DVD+R" don't work.  One must get 
"DVD-R."

	Is this the experience of the folks here?  What is the difference?  
Why does one work and one not?

	TIA

											Peter