1. rpm -q --requires somepackagehere

  2. One is the i?86 package, the other is the x86_64 package.


The yum deplist command will show you which rpm's are dependencies, here's an example for the expect package (this will work even if you don't yet have the package installed locally):

# yum deplist expect
..
..
package: expect.i386 5.43.0-5.1
 dependency: libc.so.6
  provider: glibc.i686 2.5-49
  provider: glibc.i686 2.5-49
 dependency: libtcl8.4.so
  provider: tcl.i386 8.4.13-4.el5