tar and permissions

[Hector Akamine <akamine@example.com>]

Hi,

I am confused about the meaning of the "preserve permissions" (-p)
switch in tar. According to what I have read, using -p keeps the file
permissions as the original files. Then, what happens when I use tar without
-p?

I want to copy the contents of some user's directory using tar. I think
I should make the operation as root. If I use -p, will it keep the
file-directory permissions and owners as the original ones? What happens
if I don't use -p? 


Thanks in advance 


-- 
Hector Akamine <akamine@example.com>