[LBo] question about using tar.gz for home backup

[Sam Morgan]

I was reading the sidux page on backing up your home:
http://sidux.com/index.php?module=pnWikka&tag=SecureHomeEN

I had been using the line:
tar cvzf /home /somewhere/home.tar.gz

they mention using:
tar -cf - /home | gzip -c9 > /somewhere/home.tar.gz

my question is would one usage of the tar and gzip command
be preferred over the other?

also I can't find what the 9 (nine) means after the -c
I'm guessing it may be something to indicate the amount of compression to be 
used by the gzip part of the command?
-- 
God Bless,
Sam Morgan
http://linuxbasics.org
linux the lifetime learning experience